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Human guanylin, coded by the GUCA2A gene, is a member of a peptide family that activates intestinal membrane guanylate cyclase, regulating electrolyte and water transport in intestinal and renal epithelia. Deregulation of guanylin peptide activity has been associated with colon adenocarcinoma, adenoma and intestinal polyps. Besides, it is known that mutations on guanylin receptors could be involved in meconium ileus. However, there are no previous works regarding the alterations driven by single nucleotide polymorphisms in guanylin peptides. A comprehensive in silico analysis of missense SNPs present in the GUCA2A gene was performed taking into account 16 prediction tools in order to select the deleterious variations for further evaluation by molecular dynamics simulations (50 ns). Molecular dynamics data suggest that the three out of five variants (Cys104Arg, Cys112Ser and Cys115Tyr) have undergone structural modifications in terms of flexibility, volume and/or solvation. In addition, two nonsense SNPs were identified, both preventing the formation of disulfide bonds and resulting in the synthesis of truncated proteins. In summary the structural analysis of missense SNPs is important to decrease the number of potential mutations to be in vitro evaluated for associating them with some genetic diseases. In addition, data reported here could lead to a better understanding of structural and functional aspects of guanylin peptides. [ABSTRACT FROM AUTHOR]

Abstract: Most antimicrobial peptides (AMPs) have shown clear activity related to the disruption of lipid bilayers. In order to improve knowledge of this subject, the interaction of Magainin I (MagI) with phospholipid layers (PLs), uncoated or coated with synperonic (Synp), was studied using cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and surface plasmon resonance (SPR) techniques. MagI peptide was immobilized on gold electrode via a self-assembling monolayer obtained from liposomes and liposomes covered by Synp. MagI induces pores in the supported lipid membranes, which are reflected in an increased amperometric-response and also a decreased electron-transfer resistance (R CT). In addition, MagI showed a significant interaction with the PL-Synp-modified gold electrode, but MagI showed a reliable contact with the PL-modified gold electrode, leading to a decrease in the relative resistance charge transfer value of −17.38%. Our results demonstrated that Synp acts as a membrane sealant after exposure of the lipid membrane to MagI. A parallel reaction model was proposed for the interaction of MagI and a hybrid layer that result in a complex bimolecular interaction. In short, the importance of triblock copolymer to stabilize liposomes for future applications as drug delivery systems for MagI was demonstrated. [Copyright &y& Elsevier]

Abstract: Talisin is a seed-storage protein from Talisia esculenta that presents lectin-like activities, as well as proteinase-inhibitor properties. The present study aims to provide new in vitro and in silico biochemical information about this protein, shedding some light on its mechanistic inhibitory strategies. A theoretical three-dimensional structure of Talisin bound to trypsin was constructed in order to determine the relative interaction mode. Since the structure of non-competitive inhibition has not been elucidated, Talisin-trypsin docking was carried out using Hex v5.1, since the structure of non-competitive inhibition has not been elucidated. The predicted non-coincidence of the trypsin binding site is completely different from that previously proposed for Kunitz-type inhibitors, which demonstrate a substitution of an Arg64 for the Glu64 residue. Data, therefore, provide more information regarding the mechanisms of non-competitive plant proteinase inhibitors. Bioassays with Talisin also presented a strong insecticide effect on the larval development of Diatraea saccharalis, demonstrating LD50 and ED50 of ca. 2.0% and 1.5%, respectively. [Copyright &y& Elsevier]

Antimicrobial peptides are an abundant group of proteinaceous compounds widely produced in the plant kingdom. Among them, the γ-thionin family, also known as plant defensins, represents one typical family and comprises low molecular mass cysteine-rich proteins, usually cationic and distributed in different plant tissues. Here, we report the purification and characterization of a novel γ-thionin from cowpea seeds ( Vigna unguiculata), named Cp-thionin II, with bactericidal activity against Gram-positive and Gram-negative bacteria. Once the primary structure was elucidated, molecular modelling experiments were used to investigate the multimerization and mechanism of action of plant γ-thionins. Furthermore, Cp-thionin II was also localized in different tissues in cowpea seedlings during germination in contrasting conditions, to better understand the plant protection processes. The use of plant defensins in the construction of transgenic plants and also in the production of novel drugs with activity against human pathogens is discussed. [ABSTRACT FROM AUTHOR]

In the present work, Aspergillus fumigatus is described as a higher producer of hydrolytic enzymes secreted in response to the presence of the Callosobruchus maculatus bruchid pest. This fungus was able to grow over cowpea weevil shells as a unique carbon source, secreting alkaline proteolytic and chitinolytic enzymes. Enzyme secretion in A. fumigatus was induced by both C. maculatus exoskeleton as well as commercial chitin, and alkaline proteolytic and chitinolytic activities were detected after 48 hours of growth. Furthermore, sodium dodecyl sulfate–polyacrylamide gel electrophoresis (SDS-PAGE) analysis showed the production of specific proteins. Among them, two extracellular alkaline proteinases from culture enriched with C. maculatus exoskeleton were purified after chromatographic procedures using ion exchange and affinity columns. These proteins, named AP15 and AP30, had apparent molecular masses of 15,500 and 30,000 Da, respectively, as estimated by SDS-PAGE electrophoresis and mass spectrometry. AP30 was classified as a serine proteinase because it was inhibited by 5 m M phenylmethylsulfonyl fluoride (100%) and 50 μM leupeptin (67.94%). [ABSTRACT FROM AUTHOR]

Abstract: This review focuses on the first plant defense protein class described in literature, with growth inhibition activity toward pathogens. These peptides were named γ-thionins or defensins, which are small proteins that can be classified into four main subtypes according to their specific functions. γ-Thionins are small cationic peptides with different and special abilities. They are able to inhibit digestive enzymes or act against bacteria and/or fungi. Current research in this area focuses particularly these two last targets, being the natural crop plant defenses improved through the use of transgenic technology. Here, we will compare primary and tertiary structures of γ-thionins and also will analyze their similarities to scorpion toxins and insect defensins. This last comparison offers some hypothesis for γ-thionins mechanisms of action against certain pathogens. This specific area has benefited from the recent determination of many γ-thionin structures. Furthermore, we also summarize molecular interactions between plant γ-thionins and fungi receptors, which include membrane proteins and lipids, shedding some light over pathogen resistance. Researches on γ-thionins targets could help on plant genetic improvement for production of increased resistance toward pathogens. Thus, positive results recently obtained for transgenic plants and future prospects in the area are also approached. Finally, γ-thionins activity has also been studied for future drug development, capable of inhibit tumor cell growth in human beings. [Copyright &y& Elsevier]

The cotton boll weevil, Anthonomus grandis, is an economically important pest of cotton in tropical and subtropical areas of several countries in the Americas, causing severe losses due to their damage in cotton floral buds. Enzymatic assays using gut extracts from larval and adult boll weevil have demonstrated the presence of digestive serine proteinase-like activities. Furthermore, in vitro assays showed that soybean Kunitz trypsin inhibitor (SKTI) was able to inhibit these enzymes. Previously, in vivo effects of black-eyed pea trypsin chymotrypsin inhibitor (BTCI) have been demonstrated towards the boll weevil pest. Here, when neonate larvae were reared on an artificial diet containing SKTI at three different concentrations, a reduction of larval weight of up to 64% was observed for highest SKTI concentration 500 μM. The presence of SKTI caused an increase in mortality and severe deformities of larvae, pupae and adult insects. This work therefore represents the first observation of a Kunitz trypsin inhibitor active in vivo and in vitro against A. grandis. Bioassays suggested that SKTI could be used as a tool in engineering crop plants, which might exhibit increased resistance against cotton boll weevil. [Copyright &y& Elsevier]

The cotton boll weevil Anthonomus grandis (Boheman) is one of the major pests of cotton (Gossypium hirsutum L.) in tropical and sub-tropical areas of the New World. This feeds on cotton floral fruits and buds causing severe crop losses. Digestion in the boll weevil is facilitated by high levels of serine proteinases, which are responsible for the almost all proteolytic activity. Aiming to reduce the proteolytic activity, the inhibitory effects of black-eyed pea trypsin/chymotrypsin inhibitor (BTCI), towards trypsin and chymotrypsin from bovine pancreas and from midguts of A. grandis larvae and adult insects were analyzed. BTCI, purified from Vigna unguiculata (L.) seeds, was highly active against different trypsin-like proteinases studied and moderately active against the digestive chymotrypsin of adult insects. Nevertheless, no inhibitory activity was observed against chymotrypsin from A. grandis larval guts. To test the BTCI efficiency in vivo, neonate larvae were reared on artificial diet containing BTCI at 10, 50 and 100 μM. A reduction of larval weight of up to approximately 54% at the highest BTCI concentration was observed. At this concentration, the insect mortality was 65%. This work constitutes the first observation of a Bowman–Birk type inhibitor active in vitro and in vivo toward the cotton boll weevil A. grandis. The results of bioassays strongly suggest that BTCI may have potential as a transgene protein for use in engineered crop plants modified for heightened resistance to the cotton boll weevil. [Copyright &y& Elsevier]

X-ray crystallography and bioinformatics studies reveal a tendency for the right-handed β-helix domain architecture to be associated with carbohydrate binding proteins. Here we demonstrate the presence of catalytic β-helix domains in glycoside hydrolase (GH) families 49, 55 and 87 and provide evidence for their sharing a common evolutionary ancestor with two structurally characterized GH families, numbers 28 and 82. This domain assignment helps assign catalytic residues to each family. Further analysis of domain architecture reveals the association of carbohydrate binding modules with catalytic GH β-helices, as well as an unexpected pair of β-helix domains in GH family 55. [Copyright &y& Elsevier]

Insect pests and pathogens (fungi, bacteria and viruses) are responsible for severe crop losses. Insects feed directly on the plant tissues, while the pathogens lead to damage or death of the plant. Plants have evolved a certain degree of resistance through the production of defence compounds, which may be aproteic, e.g. antibiotics, alkaloids, terpenes, cyanogenic glucosides or proteic, e.g. chitinases, β-1,3-glucanases, lectins, arcelins, vicilins, systemins and enzyme inhibitors. The enzyme inhibitors impede digestion through their action on insect gut digestive α-amylases and proteinases, which play a key role in the digestion of plant starch and proteins. The natural defences of crop plants may be improved through the use of transgenic technology. Current research in the area focuses particularly on weevils as these are highly dependent on starch for their energy supply. Six different α-amylase inhibitor classes, lectin-like, knottin-like, cereal-type, Kunitz-like, γ-purothionin-like and thaumatin-like could be used in pest control. These classes of inhibitors show remarkable structural variety leading to different modes of inhibition and different specificity profiles against diverse α-amylases. Specificity of inhibition is an important issue as the introduced inhibitor must not adversely affect the plant's own α-amylases, nor the nutritional value of the crop. Of particular interest are some bifunctional inhibitors with additional favourable properties, such as proteinase inhibitory activity or chitinase activity. The area has benefited from the recent determination of many structures of α-amylases, inhibitors and complexes. These structures highlight the remarkable variety in structural modes of α-amylase inhibition. The continuing discovery of new classes of α-amylase inhibitor ensures that exciting discoveries remain to be made. In this review, we summarize existing knowledge of insect α-amylases, plant... [ABSTRACT FROM AUTHOR]

Many factors contribute to bacterial membrane stabilization, including steric effects between lipids, membrane spontaneous curvature, and the difference in the number of neighboring molecules. This forum provides an overview of the physicochemical properties associated with membrane curvature and how this parameter can be tuned to design more effective antimicrobial peptides. [ABSTRACT FROM AUTHOR]

Mastoparans are cationic peptides with multifunctional pharmacological properties. Mastoparan-R1 and mastoparan-R4 were computationally designed based on native mastoparan-L from wasps and have improved therapeutic potential for the control of bacterial infections. Here, we evaluated whether these peptides maintain their activity against Escherichia coli strains under a range of salt concentrations. We found that mastoparan- R1 and mastoparan-R4 preserved their activity under the conditions tested, including having antibacterial activities at physiological salt concentrations. The overall structure of the peptides was investigated using circular dichroism spectroscopy in a range of solvents. No significant changes in secondary structure were observed (random coil in aqueous solutions and a-helix in hydrophobic and anionic environments). The three-dimensional structures of mastoparan-R1 and mastoparan-R4 were elucidated through nuclear magnetic resonance spectroscopy, revealing amphipathic a-helical segments for Leu3-Ile13 (mastoparan-R1) and Leu3-Ile14 (mastoparan- R4). Possible membrane-association mechanisms for mastoparan-R1 and mastoparan-R4 were investigated through surface plasmon resonance and leakage studies with synthetic POPC and POPC/POPG (4:1) lipid bilayers. Mastoparan-L had the highest affinity for both membrane systems, whereas the two analogs had weaker association, but improved selectivity for lysing anionic membranes. This finding was also supported by molecular dynamics simulations, in which mastoparan-R1 and mastoparan-R4 were found to have greater interactions with bacteria-like membranes compared with model mammalian membranes. Despite having a few differences in their functional and structural profiles, the mastoparan-R1 analog stood out with the highest activity, greater bacteriostatic potential, and selectivity for lysing anionic membranes. This study reinforces the potential of mastoparan-R1 as a drug candidate. [ABSTRACT FROM AUTHOR]

[Display omitted] • Nanofibers are excellent candidates for drug delivery antimicrobial peptides (AMPs). • Electrospinning and self-assembly are the main production methods for nanofibers containing AMPs. • Nanofibers containing AMPs have potential as wound dressings, as coatings for protheses, and in tissue engineering. Microbial infections are a major worldwide public health problem because a number of microorganisms can show drug resistance. Antimicrobial peptides (AMPs) are small biomolecules that present antimicrobial and immunomodulatory activities. Despite their great potential, there are still many barriers to the formulation of these molecules. In this context, nanotechnological approaches such as nanofibers are candidate drug-delivery systems for AMP formulations. These nanomaterials have a large contact surface and may carry several AMPs (single or multilayer), directing them to specific targets. Thus, this review describes the main advances related to the use of nanofibers as drug-delivery systems for AMPs. These strategies can contribute directly to the design of new multifunctional wound dressings, coatings for prostheses, and tissue engineering applications. [ABSTRACT FROM AUTHOR]

Background The synthetic antimicrobial peptide, PaDBS1R1, has been reported as a powerful anti- Klebsiella pneumoniae antimicrobial. However, there is only scarce knowledge about whether K. pneumoniae could develop resistance against PaDBS1R1 and which resistance mechanisms could be involved. Objectives Identify via label-free shotgun proteomics the K. pneumoniae resistance mechanisms developed against PaDBS1R1. Methods An adaptive laboratory evolution experiment was performed to obtain a PaDBS1R1-resistant K. pneumoniae lineage. Antimicrobial susceptibility was determined through microdilution assay. Modifications in protein abundances between the resistant and sensitive lineages were measured via label-free quantitative shotgun proteomics. Enriched Gene Ontology terms and KEGG pathways were identified through over-representation analysis. Data are available via ProteomeXchange with identifier PXD033020. Results K. pneumoniae ATCC 13883 parental strain challenged with increased subinhibitory PaDBS1R1 concentrations allowed the PaDBS1R1-resistant K. pneumoniae lineage to emerge. Proteome comparisons between PaDBS1R1-resistant K. pneumoniae and PaDBS1R1-sensitive K. pneumoniae under PaDBS1R1-induced stress conditions enabled the identification and quantification of 1702 proteins, out of which 201 were differentially abundant proteins (DAPs). The profiled DAPs comprised 103 up-regulated proteins (adjusted P value < 0.05, fold change ≥ 2) and 98 down-regulated proteins (adjusted P value < 0.05, fold change ≤ 0.5). The enrichment analysis suggests that PhoPQ-guided LPS modifications and CpxRA-dependent folding machinery could be relevant resistance mechanisms against PaDBS1R1. Conclusions Based on experimental evolution and a label-free quantitative shotgun proteomic approach, we showed that K. pneumoniae developed resistance against PaDBS1R1, whereas PhoPQ-guided LPS modifications and CpxRA-dependent folding machinery appear to be relevant resistance mechanisms against PaDBS1R1. [ABSTRACT FROM AUTHOR]

• Cyclotides are short disulfide rich peptides isolated from several plant families. • Cyclotides have a head to tail cyclized backbone structure. • The structure of cyclotides displays exceptional stability and sequence plasticity. • This family has shown a range of pharmaceutical and agrochemical activities. • Cyclotides appear as promising leads for peptide-based therapeutics. Cyclotides are cyclic peptides, present in several plant families, that show diverse biological properties. Structurally, cyclotides share a distinctive head-to-tail circular knotted topology of three disulfide bonds. This framework provides cyclotides with extraordinary resistance to thermal and chemical denaturation. There is increasing interest in the therapeutic potential of cyclotides, which combine several promising pharmaceutical properties, including binding affinity, target selectivity, and low toxicity towards healthy mammalian cells. Recently, cyclotides have been reported to be orally bioavailable and have proved to be amenable to modifications. Here, we provide an overview of the structure, properties, and pharmaceutical applications of cyclotides. [ABSTRACT FROM AUTHOR]

Several minimal media capable of inducing pathogenicity genes have been used to study plant-pathogen interactions. An in planta assay to study a closer interaction between the bacteria and the host was also developed and has been employed by our group. In order to determine whether growth medium could be improved to better approximate in planta conditions beyond that offered by the defined minimal medium XVM1, we compared the expression of 20 Xanthomonas campestris pv. campestris (Xcc) genes by quantitative reverse transcription - polymerase chain reaction (qRT-PCR) under in vivo (bacteria recovered from the plant) and in vitro (rich medium NYG, minimal medium XVM1 and XVM1 + leaf extract) growth systems. The results showed a higher expression level of the genes in the in planta system when compared to growth in culture media. In planta growth is closest to a real interaction condition and captures the complexity of the plant cell environment; however, this system has some limitations. The main finding of our work is that the addition of plant extract to XVM1 medium results in a gene expression profile that better matches the in planta profile, when compared with the XVM1 medium alone, giving support to the use of plant extract to study pathogenicity mechanisms in Xanthomonas. [ABSTRACT FROM AUTHOR]

Lovastatin, composed of secondary metabolites produced by filamentous fungi, is the most frequently used drug for hypercholesterolemia treatment due to the fact that lovastatin is a competitive inhibitor of HMG-CoA reductase. Moreover, recent studies have shown several important applications for lovastatin including antimicrobial agents and treatments for cancers and bone diseases. Studies regarding the lovastatin biosynthetic pathway have also demonstrated that lovastatin is synthesized from two-chain reactions using acetate and malonyl-CoA as a substrate. It is also known that there are two key enzymes involved in the biosynthetic pathway called polyketide synthases (PKS). Those are characterized as multifunctional enzymes and are encoded by specific genes organized in clusters on the fungal genome. Since it is a secondary metabolite, cultivation process optimization for lovastatin biosynthesis has included nitrogen limitation and non-fermentable carbon sources such as lactose and glycerol. Additionally, the influences of temperature, pH, agitation/aeration, and particle and inoculum size on lovastatin production have been also described. Although many reviews have been published covering different aspects of lovastatin production, this review brings, for the first time, complete information about the genetic basis for lovastatin production, detection and quantification, strain screening and cultivation process optimization. Moreover, this review covers all the information available from patent databases covering each protected aspect during lovastatin bio-production. [ABSTRACT FROM AUTHOR]

Bovine mastitis is a frequent infection in lactating cattle, causing great economic losses. Staphylococcus aureus represents the main etiological agent, which causes recurrent and persistent intramammary infections because conventional antibiotics are ineffective against it. Mastoparan-like peptides are multifunctional molecules with broad antimicrobial potential, constituting an attractive alternative. Nevertheless, their toxicity to host cells has hindered their therapeutic application. Previously, our group engineered three mastoparan-L analogs, namely mastoparan-MO, mastoparan-R1, and [I5, R8] MP, to improve cell selectivity and potential. Here, we were interested in comparing the antibacterial efficacy of mastoparan-L and its analogs against bovine mastitis isolates of S. aureus strains, making a correlation with the physicochemical properties and structural arrangement changes promoted by the sequence modifications. As a result, the analog's hemolytic and/or antimicrobial activity was balanced. All the peptides displayed α-helical folding in hydrophobic and membrane-mimetic environments, as determined by circular dichroism. The peptide [I5, R8] MP stood out for its enhanced selectivity and antibacterial features related to mastoparan-L and the other derivatives. Biophysical approaches revealed that [I5, R8] MP rapidly depolarizes the bacterial membrane of S. aureus, causing cell death by subsequent membrane disruption. Our results demonstrated that the [I5, R8] MP peptide could be a starting point for the development of peptide-based drugs for the treatment of bovine mastitis, with the advantage of no residue in milk, which would help reduce the use of classical antibiotics. [ABSTRACT FROM AUTHOR]

This work aims to investigate the possible mechanism of action of the homologue peptide Pa -MAP based on the Antarctic fish Pleuronectes americanus , through a study by electrical impedance spectroscopy (EIS) of models of bilayer lipid membranes supported (BLM-s) on solid substrates. For comparison and validation of the data obtained by EIS, we also conducted a study evaluating the human peptide LL-37, whose mechanism of action is well described in the literature: its dielectric response was found to be similar to that of Pa -MAP. The results obtained indicate that Pa -MAP has a good potential for use as a membrane-disrupting peptide and also suggest that the corresponding mechanism of action occurs according to the carpet model followed by a detergent-like effect. The addition of either one of these peptides at different concentrations resulted in a drastic decrease in the membrane's resistance, after just 1 min of exposure. Additionally, it was seen that the peptides Pa -MAP and LL-37 may act on membranes with different charges, in an indication of a possible broad spectrum antimicrobial activity. These interactions with different membrane compositions have been attributed to the peptides' structure, mainly due to the presence of many hydrophobic amino acid residues, as observed by in silico studies. Here, we describe the Pa -MAP mechanism of action for the first time. Furthermore, we report the data demonstrating that EIS can be used for studies of peptide–membranes interaction, even when small changes on the surface of the electrode can be detected. [ABSTRACT FROM AUTHOR]

Antimicrobial peptides (AMPs) are pinpointed as promising molecules against antibiotic-resistant bacterial infections. Nevertheless, there is a discrepancy between the AMP sequences generated and the tangible outcomes in clinical trials. AMPs' limitations include enzymatic degradation, chemical/physical instability and toxicity toward healthy human cells. These factors compromise AMPs' bioavailability, resulting in limited therapeutic potential. To overcome such obstacles, peptidomimetic approaches, including glycosylation, PEGylation, lipidation, cyclization, grafting, D -amino acid insertion, stapling and dendrimers are promising strategies to fine-tune AMPs. Here we focused on chemical modifications applied for AMP optimization and how they have helped these peptide-based antibiotic candidates' design and translational potential. [ABSTRACT FROM AUTHOR]

Abstract: Plant cyclotides are unusual peptides with low molecular masses and a three-dimensional structure characterized by the presence of a cyclic fold. Synthetic peptides can adopt this circular conformation, but it is not a common feature for most members of other peptide groups. Cyclotides present a wide range of functions, such as the ability to induce stronger contractions during childbirth and anti-tumor activity. Additionally, some cyclotides present anti-viral, insecticidal or proteinase inhibitory activity. In this paper, we describe the structural and functional characteristics of plant cyclotides, their most conserved features and the development of these peptides for human health and biotechnological applications. [Copyright &y& Elsevier]

Cysteine proteinases from larvae of the common bean weevil, Acanthoscelides obtectus (Coleoptera: Bruchidae), were isolated by ion exchange affinity chromatography on a CM-Cellulose column and used to select mutant cystatins from a library made with the filamentous M13 phage display system. The library contained variant cystatins derived from the nematode Onchocerca volvulus cystatin through mutagenesis of loop 1, which contains the QVVAG motif that is involved in binding to proteinases. After three rounds of selection, the activity of variant cystatins against papain and cysteine proteinases from A. obtectus was assayed by ELISA. Two different variant cystatins (presenting amino acids DVVSA and NTSSA at positions 65–69) bound to A. obtectus cysteine proteinases more tightly than to papain. In contrast, the wild type had similar affinity for A. obtectus proteinases and for papain. These two selected variants cystatins have greater specificity towards A. obtectus cysteine proteinases than the original sequence and could represent good candidate genes for the production of transgenic plants resistant to this insect pest. [Copyright &y& Elsevier]

Objectives: In order to evaluate host defense peptides (HDPs) HHC-10 and synoeca-MP activity in in vitro osteoclastogenesis process and in vivo induced apical periodontitis, testing the effect of molecules in the inflammatory response and in apical periodontitis size/volume after root canal treatment. Materials and methods: In vitro osteoclastogenesis was assessed on bone marrow cell cultures extracted from mice, while in vivo endodontic treatment involved rats treated with Ca(OH)2 or HDPs. In vitro osteoclasts were subjected to TRAP staining, and in vivo samples were evaluated by radiographic and tomographic exams, as well as histologic analysis. Results: None of the substances downregulated the in vitro osteoclastogenesis. Nevertheless, all treatments affected the average of apical periodontitis size in rats, although only teeth treated with HDPs demonstrated lower levels of the inflammatory process. These results demonstrated the in vivo potential of HDPs. Radiographic analysis suggested that HHC-10 and synoeca-MP-treated animals presented a similar lesion size than Ca(OH)2-treated animals after 7-day of endodontic treatment. However, tomography analysis demonstrated smaller lesion volume in synoeca-MP-treated animals than HHC-10 and Ca(OH)2-treated animals, after 7 days. Conclusions: These molecules demonstrated an auxiliary effect in endodontic treatment that might be related to its immunomodulatory ability, broad-spectrum antimicrobial activity, and possible induction of tissue repair at low concentrations. These results can encourage further investigations on the specific mechanisms of action in animal models to clarify the commercial applicability of these biomolecules for endodontic treatment. Clinical significance: HDPs have the potential to be adjuvant substances in endodontic therapy due to its potential to reduce inflammation in apical periodontitis. [ABSTRACT FROM AUTHOR]

Objectives: The number of bacterial pathogens resistant to the currently available antibiotics has dramatically increased, with antimicrobial peptides (AMPs) being among the most promising potential new drugs. In this study, the applicability and mechanisms of action of Pa-MAP 2 and Pa-MAP 1.9, two AMPs synthetically designed based on a natural AMP template, were evaluated.Methods: Pa-MAP 2 and Pa-MAP 1.9 were tested against a clinically isolated multidrug-resistant (MDR) Escherichia coli strain. Biophysical approaches were used to evaluate the preference of both peptides for specific lipid membranes, and bacterial surface changes imaged by atomic force microscopy (AFM). The efficacy of both peptides was assessed both in vitro and in vivo.Results: Experimental results showed that both peptides have antimicrobial activity against the E. coli MDR strain. Zeta potential and surface plasmon resonance assays showed that they interact extensively with negatively charged membranes, changing from a random coil structure, when free in solution, to an α-helical structure after membrane interaction. The antibacterial efficacy was evaluated in vitro, by several techniques, and in vivo, using a wound infection model, showing a concentration-dependent antibacterial effect. Different membrane properties were evaluated to understand the mechanism underlying peptide action, showing that both promote destabilization of the bacterial surface, as imaged by AFM, and change properties such as membrane surface and dipole potential.Conclusions: Despite their similarity, data indicate that the mechanisms of action of the peptides are different, with Pa-MAP 1.9 being more effective than Pa-MAP 2. These results highlight their potential use as antimicrobial agents against MDR bacteria. [ABSTRACT FROM AUTHOR]

The spread of multi-drug resistance and the slow pace at which antibiotics come onto the market are undermining our ability to treat human infections, leading to high mortality rates. Aiming to overcome this global crisis, antimicrobial peptides are considered promising alternatives to counter bacterial infections with multi-drug resistant bacteria. The cathelicidins comprise a well-studied class of AMPs whose members have been used as model molecules for sequence modifications, aiming at enhanced biological activities and stability, along with reduced toxic effects on mammalian cells. Here, we describe the antimicrobial activities, modes of action and structural characterization of two novel cathelicidin-like peptides, named BotrAMP14 and CrotAMP14, which were re-designed from snake batroxicidin and crotalicidin, respectively. BotrAMP14 and CrotAMP14 showed broad-spectrum antibacterial activity against susceptible microorganisms and clinical isolates with minimal inhibitory concentrations ranging from 2–35.1 μM. Moreover, both peptides had low cytotoxicity against Caco-2 cells in vitro. In addition, in vivo toxicity against Galleria mellonella moth larvae revealed that both peptides led to>76% larval survival after 144 h. Microscopy studies suggest that BotrAMP14 and CrotAMP14 destabilize E. coli membranes. Furthermore, circular dichroism and molecular dynamics simulations indicate that, in a membrane-like environment, both peptides adopt α-helical structures that interact with bilayer phospholipids through hydrogen bonds and electrostatic interaction. Thus, we concluded that BotrAMP14 and CrotAMP14 are helical membrane active peptides, with similar antibacterial properties but lower cytotoxicity than the larger parent peptides batroxicidin and crotalicidin, having advantages for drug development strategies. [ABSTRACT FROM AUTHOR]

The rising number of multidrug‐resistant microorganisms has triggered interest in the prospection of biocompounds with antimicrobial activities. Synoeca‐MP consists of an antimicrobial peptide (AMP) classified as a mastoparan, which was isolated from the venom of Synoeca surinama, a social wasp. Synoeca‐MP presented a potent antimicrobial activity, with values of MIC50 and MIC90 against methicillin‐resistant Staphylococcus aureus—MRSA (1.9 and 2.2 μM), Escherichia coli ESBL (2.0 and 2,1 μM), vancomycin‐resistant Enterococcus faecalis (8.3 and 17.1 μM), Pseudomonas aeruginosa metallo‐ß‐lactamase (5.2 and 5.9 μM), and Klebsiella pneumoniae KPC (3.5 and 4.7 μM). Synoeca‐MP was also tested against six Candida species, with MICs varying from 10 to 40 μM. Moreover, the structural prediction for Synoeca‐MP demonstrated a cationic α‐helix capable of interacting with in silico membranes and low hemolytic activity. Due to its antimicrobial activity, synoeca‐MP shows potential as an adjuvant to antibiotics and antifungals commonly used in antibiotic therapies. [ABSTRACT FROM AUTHOR]

‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬This study aims to evaluate the in vitro antimicrobial and immunomodulatory activities and cytotoxicity of chlorhexidine (CHX) and synoeca‐MP peptide alone or in combination against Pseudomonas aeruginosa. The antimicrobial property was evaluated by the determination of minimal inhibitory concentration, minimum bactericidal concentration, and planktonic bacteria and biofilm inhibition. Immunomodulatory activity was determined by enzyme‐linked immunosorbent assay and nitric oxide production by the Griess reaction method. According to the results, synoeca‐MP combined with CHX demonstrated antimicrobial effectiveness compared with its isolated use, in addition to immunomodulatory activity (upregulating MPC‐1 and tumor necrosis factor‐α and downregulating nitric oxide and interleukin‐10). In this context, it is expected that the substances, together, could be capable of controlling bacterial infection and dissemination, besides potentiating macrophages' immune response against the studied microorganism. Moreover, reducing the CHX concentration by the addition of synoeca‐MP peptide may, in a beneficial way, minimize the undesirable effects of both, CHX and synoeca‐MP in a clinical setting. [ABSTRACT FROM AUTHOR]

The article provides an overview of seventeen articles on topics related to biotransformation and bioactivation reactions published in 2018 which includes the article on drug optimization "Structure-function-guided Exploration of the Antimicrobial Peptide Polybia-CP Identifies Activity Determinants and Generates Synthetic Therapeutic Candidate," by Marcelo D.T. Torres, Cibele N. Pedron, Yasutomi Higashikuni, Robin M. Kramer, Marlon H. Cardoso, Karen G.N. Oshiro, Octavio L. Franco, Pedro I. Silva Junior, Fernanda D. Silva, Vani X. Oliveira Junior, Timothy K. Lu,and Cesar de la Fuente-Nunez, which appeared in the 2017 1:221 issue of "Community Biology;" an article on metabolites and drug metabolizing enzymes "Hydrolytic Metabolism of Cyanopyrrolidine DPP-4 Inhibitors Mediated by Dipeptidyl Peptidases," by Kong F, Pang X, Zhao J, Deng P, Zheng M,Zhong D, Chen X in "Drug Metabolism and Disposition;" and "N-Methylation of BI 187004 by thiol S-methyltransferase," by Hlaing H. Maw, Xingzhong Zeng, Scot Campbell, Mitchell E. Taub and Aaron M. Teitelbaum," from the volume 48 , 2018 issue of "Drug Metabolism Disposition."

Abstract Obesity is a chronic multifactorial disease, characterized by an excessive accumulation of adipose tissue. It is usually the result of excessive food intake and/or low energy expenditure. Obesity can be triggered by lifestyle, nutritional, genetic, environmental, hormonal and psychological factors. Several strategies are used to treat obesity, including dietary reeducation, with balanced food intake, increased physical exercise, in order to promote energy expenditure and to overcome the insufficiency in weight reduction by other strategies, and administration of drugs. However, these medications are associated to undesirable side effects, resulting in a high withdrawal rate. Several studies have been focused on the development of compounds that act in the hypothalamic region where the center of the regulation of hunger and satiety is located. Some of them target the activity of endogenous peptides, such as ghrelin pancreatic polypeptide, peptide YY and neuropeptide Y, as well as their receptors. This review addresses the importance of understanding the neuropeptide/peptide hormones and their receptors for the development of novel anti-obesity compounds that may aid in weight reduction as a promising alternative for the treatment of obesity. [ABSTRACT FROM AUTHOR]

Antimicrobial peptides (AMPs) constitute promising alternatives to classical antibiotics for the treatment of drug-resistant infections, which are a rapidly emerging global health challenge. However, our understanding of the structure-function relationships of AMPs is limited, and we are just beginning to rationally engineer peptides in order to develop them as therapeutics. Here, we leverage a physicochemical-guided peptide design strategy to identify specific functional hotspots in the wasp-derived AMP polybia-CP and turn this toxic peptide into a viable antimicrobial. Helical fraction, hydrophobicity, and hydrophobic moment are identified as key structural and physicochemical determinants of antimicrobial activity, utilized in combination with rational engineering to generate synthetic AMPs with therapeutic activity in a mouse model. We demonstrate that, by tuning these physicochemical parameters, it is possible to design nontoxic synthetic peptides with enhanced sub-micromolar antimicrobial potency in vitro and anti-infective activity in vivo. We present a physicochemical-guided rational design strategy to generate peptide antibiotics. Marcelo D. T. Torres et al. turn toxic wasp-derived antimicrobial peptide polybia-CP into a viable antimicrobial with therapeutic activity in a mouse model. This study demonstrates that a physicochemical property-guided rational design strategy can be used to generate peptide antibiotics. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Peptides present great antimicrobial activity against multi drug resistant bacteria. • No cytotoxicity was observed for both peptides after 72 h. • Peptides induce pro-inflammatory effect on Raw 264.7 cells in the presence several stimuli. Abstract Hospital infections allied to bacterial resistance to antibiotics have become a major worldwide problem. In this context, antimicrobial peptides (AMPs) are presented as an alternative in the control of these resistant organisms. Besides antimicrobial effects, these molecules play a crucial role in immunity by acting as immunomodulators. These peptides can activate inflammatory cells to produce pro- and anti-inflammatory mediators. In this study we will show the activity against multi-drug resistant bacteria (MDRB) of two cathelicidins from South American pit vipers Bothrops atrox and Crotalus durissus terrificus, named batroxicidin and crotalicidin. It was observed that both peptides showed activity against MDRB and presented no hemolytic or cytotoxic activity. In addition, the ability of peptides to modulate the production of cytokines TNF-α, IL-10 and IL-6 was analyzed using Raw 264.7 cells in the presence of IFN-γ stimuli, and multi-resistant E. coli and K. pneumoniae antigens. An up-expression or down-expression of TNF-α, as well as the IL-10 mediator, was observed. The cytokine IL-6, on the other hand, presented only a down-regulation for Raw 264.7 cell groups. In conclusion, the results demonstrate that both peptides presented a predominantly proinflammatory characteristic to the inflammatory mediators dosed. Overall, even presenting a proinflammatory characteristic, these peptides are still promising for future research and development of new potential antimicrobial molecules. [ABSTRACT FROM AUTHOR]

The synthesis, structures and anticancer studies of a series of precious metal complexes supported by 1-methyl-2-(phenyl)imidazo[1,5-a]pyridine-2-ylidene (1) have been highlighted. The Ag(i) (2), Au(i) (3) and Au(iii) (4) complexes were prepared using standard methods and characterized by a range of techniques, including NMR spectroscopy, X-ray crystallography and elemental analyses. The in vitro cytotoxicity activities displayed by 2–4 were explored against human colon adenocarcinoma (HCT116), lung cancer (A549) and breast cancer (MCF7) cell lines. A series of assays showed that all of the complexes exhibited significant growth inhibition in the aforementioned cell lines. Inspection of the data collected revealed that the Au(i) and Ag(i) complexes were more potent than their Au(iii) congener, a trend that was found to be consistent with molecular docking studies that utilized BCL-2 as a model as this protein regulates cell death through apoptosis. [ABSTRACT FROM AUTHOR]

Diabetes mellitus (DM) is a metabolic disorder that results in the impairment of the metabolism of carbohydrates, proteins and lipids. It can give rise to various complications, mainly caused by chronic exposure of cells to high glucose concentrations, including changes in the immune response processes. The aim of this study was to verify the chemokine and cytokines production profile in the presence of different glucose concentrations and infection/inflammatory stimuli. To this end, cell viability and the production of chemokines, cytokines and nitric oxide (NO) were analyzed in RAW 264.7 cell culture. Results demonstrated that there was no change in cell viability after 6, 24 and 72 h. Different stimuli were unable to modify the monocyte chemoattractant protein (MCP)-1 and tumor necrosis factor (TNF)-α production. Groups stimulated with lipopolysaccharides (LPS) and LPS and recombinant interferon (rIFN)-γ down-regulated interleukin (IL)-1α, IL-10 and IL-12 and up-regulated IL-6 production. NO production maintained a pattern of increase, according to the increase in glucose concentrations, reaching its peak at 72 h. In summary, the results demonstrated that high glucose concentrations alone may be sufficient to alter the in vitro mediators’ production of RAW 264.7 cells. [ABSTRACT FROM AUTHOR]

Infectious diseases are one of the main causes of human morbidity and mortality. In the last few decades, pathogenic microorganisms' resistance to conventional drugs has been increasing, and it is now pinpointed as a major worldwide health concern. The need to search for new therapeutic options, as well as improved treatment outcomes, has therefore increased significantly, with biologically active peptides representing a new alternative. A substantial research effort is being dedicated towards their development, especially due to improved biocompatibility and target selectivity. However, the inherent limitations of peptide drugs are restricting their application. In this review, we summarize the current status of peptide drug development, focusing on antiviral and antimicrobial peptide activities, highlighting the design improvements needed, and those already being used, to overcome the drawbacks of the therapeutic application of biologically active peptides. [ABSTRACT FROM AUTHOR]

Endodontic treatment is mainly based on root canal disinfection and its failure may be motivated by microbial resistance. Endodontic therapy can be benefitted by host defense peptides (HDPs), which are multifunctional molecules that act against persistent infection and inflammation. This study aimed to evaluate the antimicrobial, cytotoxic and immunomodulatory activity of several HDPs, namely clavanin A, clavanin A modified (MO) and LL-37, compared to intracanal medication Ca(OH) 2 . HDPs and Ca(OH) 2 were evaluated by: (1) antimicrobial assays against Candida albicans and Enterococcus faecalis , (2) cytotoxicity assays and (3) cytokine tumor necrosis factor (TNF)-α, monocyte chemoattractant protein (MCP)-1, interleukin (IL)-1α, IL-6, IL-10 and IL-12 and nitric oxide (NO) production by RAW 264.7 cells incubated with or without heat-killed (HK) C. albicans or E. faecalis combined or not with interferon-γ. The minimum inhibitory concentration (MIC) was established only for E. faecalis (LL-37, 57 μM). Considering cytotoxicity, clavanin MO was able to reduce cell viability in many groups and demonstrated lowest LC 50 . The Ca(OH) 2 up-regulated the production of MCP-1, TNF-α, IL-12 and IL-6 and down-regulated IL-1α, IL-10 and NO. Clavanins up-regulated the TNF-α and NO and down-regulated IL-10 production. LL-37 demonstrated up-regulation of IL-6 and TNF-α production and down-regulation in IL-10 and NO production. In conclusion, LL-37 demonstrated better antibacterial potential. In addition, Ca(OH) 2 demonstrated a proinflammatory response, while the HDPs modulated the inflammatory response from non-interference with the active cytokines in the osteoclastogenesis process, probably promoting the health of periradicular tissues. [ABSTRACT FROM AUTHOR]

Chronic bacterial biofilms place a massive burden on healthcare due to the presence of antibiotic-tolerant dormant bacteria. Some of the conventional antibiotics such as erythromycin, vancomycin, linezolid, rifampicin etc. are inherently ineffective against Gram-negative bacteria, particularly in their biofilms. Here, we report membrane-active macromolecules that kill slow dividing stationary-phase and antibiotic tolerant cells of Gram-negative bacteria. More importantly, these molecules potentiate antibiotics (erythromycin and rifampicin) to biofilms of Gram-negative bacteria. These molecules eliminate planktonic bacteria that are liberated after dispersion of biofilms (dispersed cells). The membrane-active mechanism of these molecules forms the key for potentiating the established antibiotics. Further, we demonstrate that the combination of macromolecules and antibiotics significantly reduces bacterial burden in mouse burn and surgical wound infection models caused by Acinetobacter baumannii and Carbapenemase producing Klebsiella pneumoniae (KPC) clinical isolate respectively. Colistin, a well-known antibiotic targeting the lipopolysaccharide (LPS) of Gram-negative bacteria fails to kill antibiotic tolerant cells and dispersed cells (from biofilms) and bacteria develop resistance to it. On the contrary, these macromolecules prevent or delay the development of bacterial resistance to known antibiotics. Our findings emphasize the potential of targeting the bacterial membrane in antibiotic potentiation for disruption of biofilms and suggest a promising strategy towards developing therapies for topical treatment of Gram-negative infections. [ABSTRACT FROM AUTHOR]

• Treatment of intracellular infections requires new drug delivery vehicles. • Intracellular macrophage infections block the immune response. • Apoptotic bodies are vesicles specifically recognized by macrophages. • Antimicrobial peptides into vesicle counteract macrophage intracellular infections. Macrophage intracellular infections are difficult to treat because conventional antibiotics tend to have poor penetration of mammalian cells. As a consequence, the immune response is affected and bacteria remain protected inside macrophages. The use of antimicrobial peptides (AMPs) is one of the alternatives developed as new treatments because of their broad spectrum of action. To improve drug delivery into the intracellular space, extracellular vesicles (EVs) have emerged as an innovative strategy for drug delivery. In particular, apoptotic bodies (ApoBDs) are EVs that exhibit attraction to macrophages, which makes them a promising means of improving AMP delivery to treat macrophage intracellular infections. Here, we review important aspects that should be taken into account when developing ApoBD–AMP conjugates. [ABSTRACT FROM AUTHOR]

Anti-infective drugs have had a key role in the contemporary world, contributing to dramatically decrease mortality rates caused by infectious diseases worldwide. Antimicrobial peptides (AMPs) are multifunctional effectors of the innate immune system of mucosal surfaces and present antimicrobial activity against a range of pathogenic viruses, bacteria, and fungi. However, the discovery and development of new antibacterial drugs is a crucial step to overcome the great challenge posed by the emergence of antibiotic resistance. In this review, we outline recent advances in the development of novel AMPs with improved antimicrobial activities that were achieved through characteristic structural design. In addition, we describe recent progress made to overcome some of the major limitations that have hindered peptide biosynthesis. [ABSTRACT FROM AUTHOR]

An important aspect related to infectious pathogens is their exceptional adaptability in developing resistance, which leads to a perpetual challenge in the discovery of antimicrobial drugs with novel mechanisms of action. Among them, antimicrobial peptides (AMPs) stand out as promising anti-infective molecules. In order to overcome the high costs associated with isolation from natural sources or chemical synthesis of AMPs we propose the expression of Pa-MAP 2, a polyalanine AMP. Pa-MAP 2 was fused to an ELP-intein tag where the ELP (Elastin-like polypeptide) was used to promote aggregation and fast and cost-effective isolation after expression, and the intein was used to stimulate a controlled AMP release. For these, the vector pET21a was used to produce Pa-MAP 2 fused to the N-termini region of a modified Mxe GyrA intein followed by 60 repetitions of ELP. Purified Pa-MAP 2 showed a MIC of 25 μM against E. coli ATCC 8739. Batch fermentation demonstrated that Pa-MAP-2 can be produced in both rich and defined media at yields 50-fold higher than reported for other AMPs produced by the ELP-intein system, and in comparable yields to expression systems with protease or chemical cleavage. [ABSTRACT FROM AUTHOR]

For almost four decades, antimicrobial peptides have been studied, and new classes are being discovered. However, for therapeutic use of these molecules, issues related to the mechanism of action must be answered. In this work, the antimicrobial activity of the hairpinin MBP-1 was studied by the synthesis of two variants, one replacing cysteines and one tryptophan with alanine. Antibacterial activity was abolished in both variants. No membrane disturbance, even in concentrations higher than those required to inhibit the bacteria, was observed in SEM microscopy. The gel retardation assay showed that MBP-1 possesses a higher DNA-binding ability than variants. Finally, molecular modelling showed that the lack of cysteines resulted in structure destabilization and lack of tryptophan resulted in a less flexible peptide, with less solvent assessable surface area, both characteristics that could contribute to absence of activity. In summary, the data here reported add more information about the multiple mechanisms of action of α-hairpinins. [ABSTRACT FROM AUTHOR]

The gut microbiota presents essential functions in the immune response. The gut epithelium acts as a protective barrier and, therefore, can produce several antimicrobial peptides (AMPs) that can act against pathogenic microorganisms, including bacteria. Several factors cause a disturbance in gut microbiota, including the exacerbated and erroneous use of antibiotics. Antibiotic therapy has been closely related to bacterial resistance and is also correlated with undesired side-effects to the host, including the eradication of commensal bacteria. Consequently, this results in gut microbiota imbalance and inflammatory bowel diseases (IBD) development. In this context, AMPs in the gut epithelium play a restructuring role for gut microbiota. Some naturally occurring AMPs are selective for pathogenic bacteria, thus preserving the health microbiota. Therefore, AMPs produced by the host's epithelial cells represent effective molecules in treating gut bacterial infections. Bearing this in mind, this review focused on describing the importance of the host's AMPs in gut microbiota modulation and their role as anti-infective agents against pathogenic bacteria. [Display omitted] • The gut microbiota presents essential functions in the immune response. • AMPs in the gut epithelium play a restructuring role for gut microbiota. • AMPs modulate the gut microbiota. • Commensal bacteria express AMPs to combat pathogenic microorganisms. [ABSTRACT FROM AUTHOR]

The increasing number of multidrug resistance microorganisms is an alarming threat, and their rapid detection is essential to prevent nosocomial, foodborne, or waterborne infections. Many peptides derived from the venom of wasp Synoeca surinama have antimicrobial activity against Gram-positive and Gram-negative bacteria. Synoeca-MP, an antimicrobial peptide (AMP) from mastoparan family, seems to increase bacterial membrane permeability, promoting cytotoxicity and membrane disruption. Here Synoeca-MP was evaluated as biorecognition element tethered over chitosan-coated magnetic nanoparticles (Fe 3 O 4 -Chit). The transducing layer of the biosensor was developed from the self-assembling of 4-mercaptobenzoic acid (4-MBA) monolayer onto gold substrate. Atomic force microscopy (AFM) analyses confirmed the biointeraction between AMP and different pathogens membranes. The fabrication and performance of the biosensing assembly were characterized by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). Detection of Enterococcus faecalis (G+) , Klebsiella pneumoniae (G-) , Pseudomonas aeruginosa (G-), and Candida tropicalis was assessed in a recognition range from 101 to 105 CFU.mL−1. An instrumental limit of detection of 10 CFU.mL−1 was obtained for each specimen. However, the device presented a preferential selectivity towards Gram-negative bacteria. The proposed biosensor is a sensitive, fast, and straightforward platform for microbial detection in aqueous samples, envisaged for environmental monitoring applications. • A new electrochemical biosensor with high sensitivity towards Gram-negative species is presented. • The biosensor combines chitosan-coated magnetic nanoparticles with the antimicrobial peptide Synoeca-MP. • The sensor detected bacteria and fungi species with a LOD of 101 CFU mL−1. • The platform presented high sensitivity towards K. pneumoniae. • This biosensor stands out as a promising tool for fast microbial detection in liquid samples. [ABSTRACT FROM AUTHOR]

Cruciferous plants are important edible vegetables widely consumed around the world, including cabbage, cauli-flower and broccoli. The main disease that affects crucifer plants is black rot, caused by Xanthomonas campestris pv. campestris (Xcc). In order to better understand this specific plant–pathogen interaction, proteins responsive to Xcc infection in resistant (União) and susceptible (Kenzan) Brassica oleracea cultivars were investigated by 2-DE followed by mass spectrometry. A total of 47 variable spots were identified and revealed that in the susceptible interaction there is a clear reduction in the abundance of proteins involved in energetic metabolism and defense. It was interesting to observe that in the resistant interaction, these proteins showed an opposite behavior. Based on our results, we conclude that resistance is correlated with the ability of the plant to keep sufficient photosynthesis metabolism activity to provide energy supplies necessary for an active defense. As a follow-up study, qRT-PCR analysis of selected genes was performed and revealed that most genes showed an up-regulation trend from 5 to 15 days after inoculation (DAI), showing highest transcript levels at 15 DAI. These results revealed the gradual accumulation of transcripts providing a more detailed view of the changes occurring during different stages of the plant–pathogen interaction. Biological significance In this study we have compared cultivars of Brassica oleracea (cabbage), susceptible and resistant to black rot, by using the classical 2-DE approach. We have found that resistance is correlated with the ability of the plant to keep sufficient photosynthesis metabolism activity to provide energy supplies necessary for an active defense. [ABSTRACT FROM AUTHOR]

Pathogenic microbial biofilm, a consortium of microbial cells protected by a self-produced polymer matrix, is considered a worldwide challenge due to the inherent antibiotic resistance conferred by its lifestyle. Living, as it does, in a community of microbial organisms in a clinical situation, makes it responsible for severe and dangerous cases of infection. Combating this organisation of cells usually requires high antibiotic doses for a prolonged time, and these approaches often fail, contributing to infection persistence. In addition to therapeutic limitations, biofilms can be a source of infections when they grow in medical devices. The challenge imposed by biofilms has mobilised researchers in the entire world to prospect or develop alternatives to control biofilms. In this context, this review summarises the new frontiers that could be used in clinical circumstances in order to prevent or eliminate pathogenic biofilms. [ABSTRACT FROM AUTHOR]

Unusual methods for specific detection of pathogenic bacteria are becoming key points for control and identification of problems related to health and (bio)safety. In this context, this work aims to propose a new approach for the development of nanostructured biosensors based on carbon nanotubes (CNTs) and antimicrobial peptides for bacterial detection. Firstly, the antimicrobial peptide clavanin A (ClavA) was chemically immobilized on CNTs and surface-immobilized ClavA was used to detect Klebsiella pneumoniae , Enterococcus faecalis , Escherichia coli and Bacillus subtilis in a direct assay format. We used electrochemical impedance spectroscopy technique to evaluate the effectiveness and sensitivity of the ClavA-based biosensors by measuring the modifications in their electrochemical responses before and after incubation in presence of different bacteria concentrations. The biosensor was able to discriminate between bacteria concentrations in the 10 2 –10 6 CFU mL −1 range. Atomic force microscopy analysis confirmed the biosensor functionality for bacterial recognition. This new sensor system was capable of differentiating between Gram-positive and Gram-negative bacteria, since ClavA showed different affinities toward the pathogenic bacteria species. [ABSTRACT FROM AUTHOR]

Context: Circulating miRNAs are potential biomarkers that can be important molecules driving cell-to-cell communication. Objective: To investigate circulating muscle-specific miRNAs in recreational athletes. Materials and methods: Three miRNAs from whole plasma before and after a half-marathon were analyzed by qPCR. Results: MiR-1, −133a, and −206 significantly increased after the race. Discussion: Increased levels of miRNAs after exercise point to potential biomarkers and to the possibility of being functional players following endurance training. Conclusion: These miRNAs are potential biomarkers of muscle damage or adaptation to exercise. [ABSTRACT FROM AUTHOR]

Peptide rational design was used here to guide the creation of two novel short β-lactamase inhibitors, here named dBLIP-1 and -2, with length of five amino acid residues. Molecular modeling associated with peptide synthesis improved bactericidal efficacy in addition to amoxicillin, ampicillin and cefotaxime. Docked structures were consistent with calorimetric analyses against bacterial β-lactamases. These two compounds were further tested in mice. Whereas commercial antibiotics alone failed to cure mice infected with Staphylococcus aureus and Escherichia coli expressing β-lactamases, infection was cleared when treated with antibiotics in combination with dBLIPs, clearly suggesting that peptides were able to neutralize bacterial resistance. Moreover, immunological assays were also performed showing that dBLIPs were unable to modify mammalian immune response in both models, reducing the risks of collateral effects. In summary, the unusual peptides here described provide leads to overcome β-lactamase-based resistance, a remarkable clinical challenge. [ABSTRACT FROM AUTHOR]

Despite all the dental information acquired over centuries and the importance of proteome research, the cross-link between these two areas only emerged around mid-nineties. Proteomic tools can help dentistry in the identification of risk factors, early diagnosis, prevention, and systematic control that will promote the evolution of treatment in all dentistry specialties. This review mainly focuses on the evolution of dentistry in different specialties based on proteomic research and how these tools can improve knowledge in dentistry. The subjects covered are an overview of proteomics in dentistry, specific information on different fields in dentistry (dental structure, restorative dentistry, endodontics, periodontics, oral pathology, oral surgery, and orthodontics) and future directions. There are many new proteomic technologies that have never been used in dentistry studies and some dentistry areas that have never been explored by proteomic tools. It is expected that a greater integration of these areas will help to understand what is still unknown in oral health and disease. J. Cell. Physiol. 228: 2271-2284, 2013. © 2013 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

• New set of Ru-N-Heterocyclic Carbene (Ru-NHC) complexes 1a and 2a were synthesized from NHC ligands. • X-RD structure reveals the half-sandwich geometry of the compounds. • Absorption spectra show the mixed-mode MLCT type transitions. • The compounds show irreversible oxidation in the cyclic voltammograms. • The compounds have exhibited very promising cytotoxic activity against a series of tumor cell lines with optimistic impressive IC 50 values. • This promising observation may lead to new drug molecules in tumor-selective therapeutic strategies. New set of Ru-N-Heterocyclic Carbene (Ru-NHC) complexes 1a and 2a were synthesized from their ligand precursors 1-Methyl-2-pyridin-2-yl-2H-imidazo[1,5-a]pyridin-4-ylium hexafluorophosphate (1) and 1-Methyl-2-pyrimidin-2-yl-2H-imidazo[1,5-a]pyridin-4-ylium hexafluorophosphate (2). The molecules were characterized and their structures were investigated through single crystals X-ray diffraction. The overall coordination around the Ru center can be described as a half-sandwich geometry. Absorption spectra and electrochemical behavior of the complexes were also evaluated, supported by DFT analysis. The complexes were applied on lung (A549), colon (HCT116) and breast (MCF7) cancer cells to examine their in vitro cytotoxicity activity. [Display omitted] [ABSTRACT FROM AUTHOR]