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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]

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]

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]

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]

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]

Exercise is recognized to prevent and attenuate several metabolic and cardiovascular disorders. Obesity is commonly related to cardiovascular diseases, frequently resulting in heart failure and death. To elucidate the effects of acute exercise in heart tissue from obese animals, 12-week-old C57BL6/J obese (ob/ob) and non-obese (ob/OB) mice were submitted to a single bout of swimming and had their hearts analyzed by proteomic techniques. Mice were divided into three groups: control (ob/ob, n = 3; ob/OB, n = 3); a moderate intensity consisting of 20 min of swimming around 90% of Maximal Lactate Steady State (ob/ob, n = 3; ob/OB, n = 3), and a high intensity exercise performed as an incremental overload test (ob/ob, n = 3; ob/OB, n = 3). Obesity modulations were analyzed by comparing ob/ob and ob/OB control groups. Differential 2-DE analysis revealed that single session of exercise was able to up-regulate: myoglobin (ob/ob), aspartate aminotransferase (ob/OB) and zinc finger protein (ob/OB) and down-regulate: nucleoside diphosphate kinase B (ob/OB), mitochondrial aconitase (ob/ob and ob/OB) and fatty acid binding protein (ob/ob). Zinc finger protein and α-actin were up-regulated by the effect of obesity on heart proteome. These data demonstrate the immediate response of metabolic and stress-related proteins after exercise so as contractile protein by obesity modulation on heart proteome. J. Cell. Physiol. 228: 824-834, 2013. © 2012 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

Exercise research has always drawn the attention of the scientific community because it can be widely applied to sport training, health improvement, and disease prevention. For many years numerous tools have been used to investigate the several physiological adaptations induced by exercise stimuli. Nowadays a closer look at the molecular mechanisms underlying metabolic pathways and muscular and cardiovascular adaptation to exercise are among the new trends in exercise physiology research. Considering this, to further understand these adaptations as well as pathology attenuation by exercise, several studies have been conducted using molecular investigations, and this trend looks set to continue. Through enormous biotechnological advances, proteomic tools have facilitated protein analysis within complex biological samples such as plasma and tissue, commonly used in exercise research. Until now, classic proteomic tools such as one- and two-dimensional polyacrylamide gel electrophoresis have been used as standard approaches to investigate proteome modulation by exercise. Furthermore, other recently developed in gel tools such as differential gel electrophoresis (DIGE) and gel-free techniques such as the protein labeling methods (ICAT, SILAC, and iTRAQ) have empowered proteomic quantitative analysis, which may successfully benefit exercise proteomic research. However, despite the three decades of 2-DE development, neither classic nor novel proteomic tools have been convincingly explored by exercise researchers. To this end, this review gives an overview of the directions in which exercise-proteome research is moving and examines the main tools that can be used as a novel strategy in exercise physiology investigation. J. Cell. Physiol. 227: 885-898, 2012. © 2011 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

Over the years, several studies have been performed to analyse plant–pathogen interactions. Recently, functional genomic strategies, including proteomics and transcriptomics, have contributed to the effort of defining gene and protein function and expression profiles. Using these ‘omic’ approaches, pathogenicity- and defence-related genes and proteins expressed during phytopathogen infections have been identified and enormous datasets have been accumulated. However, the understanding of molecular plant–pathogen interactions is still an intriguing area of investigation. Proteomics has dramatically evolved in the pursuit of large-scale functional assignment of candidate proteins and, by using this approach, several proteins expressed during phytopathogenic interactions have been identified. In this review, we highlight the proteins expressed during plant–virus, plant–bacterium, plant–fungus and plant–nematode interactions reported in proteomic studies, and discuss these findings considering the advantages and limitations of current proteomic tools. [ABSTRACT FROM AUTHOR]