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Intracellular calcium (Ca2+) is ubiquitous to cell signaling across biology. While existing fluorescent sensors and reporters can detect activated cells with elevated Ca2+ levels, these approaches require implants to deliver light to deep tissue, precluding their noninvasive use in freely behaving animals. Here we engineered an enzyme-catalyzed approach that rapidly and biochemically tags cells with elevated Ca2+ in vivo. Ca2+-activated split-TurboID (CaST) labels activated cells within 10 min with an exogenously delivered biotin molecule. The enzymatic signal increases with Ca2+ concentration and biotin labeling time, demonstrating that CaST is a time-gated integrator of total Ca2+ activity. Furthermore, the CaST readout can be performed immediately after activity labeling, in contrast to transcriptional reporters that require hours to produce signal. These capabilities allowed us to apply CaST to tag prefrontal cortex neurons activated by psilocybin, and to correlate the CaST signal with psilocybin-induced head-twitch responses in untethered mice.

[Display omitted] The rapid, precise identification and quantification of specific biomarkers, toxins, or pathogens is currently a key strategy for achieving more efficient diagnoses. Herein a dopamine-biotin monomer was synthetized and oxidized in the presence of hexamethylenediamine, to obtain adhesive coatings based on polydopamine-biotin (PDA-BT) on different materials to be used in targeted molecular therapy. Insight into the structure of the PDA-BT coating was obtained by solid-state 13C NMR spectroscopy acquired, for the first time, directly onto the coating, deposited on alumina spheres. The receptor binding capacity of the PDA-BT coating toward 4-hydroxyazobenzene-2-carboxylic acid/Avidin complex was verified by means of UV– vis spectroscopy. Different deposition cycles of avidin onto the PDA-BT coating by layer-by-layer assembly showed that the film retains its receptor binding capacity for at least eight consecutive cycles. Finally, the feasibility of PDA-BT coating to recognize cell lines with different grade of overexpression of biotin receptors (BR) was investigated by tumor cell capture experiments by using MCF-7 (BR+) and HL-60 (BR−) cell lines. The results show that the developed system can selectively capture MCF-7 cells indicating that it could represent a first approach for the development of future more sophisticated biosensors easily accessible, low cost and recyclable with the dual and rapid detection of both proteins and cells. [ABSTRACT FROM AUTHOR]

Undernutrition remains a global struggle and is associated with almost 45% of deaths in children younger than 5 years. Despite advances in management of severe wasting (though less so for nutritional edema), full and sustained recovery remains elusive. Children with severe wasting and/or nutritional edema (also commonly referred to as severe acute malnutrition and part of the umbrella term "severe malnutrition") continue to have a high mortality rate. This suggests a likely multifactorial etiology that may include micronutrient deficiency. Micronutrients are currently provided in therapeutic foods at levels based on expert opinion, with few supportive studies of high quality having been conducted. This narrative review looks at the knowledge base on micronutrient deficiencies in children aged 6–59 months who have severe wasting and/or nutritional edema, in addition to highlighting areas where further research is warranted (See "Future Directions" section). [ABSTRACT FROM AUTHOR]

The covalently attached cofactor biotin plays pivotal roles in central metabolism. The top-priority ESKAPE-type pathogens, Acinetobacter baumannii and Klebsiella pneumoniae, constitute a public health challenge of global concern. Despite the fact that the late step of biotin synthesis is a validated anti-ESKAPE drug target, the primary stage remains fragmentarily understood. We report the functional definition of two BioC isoenzymes (AbBioC for A. baumannii and KpBioC for K. pneumoniae) that act as malonyl-ACP methyltransferase and initiate biotin synthesis. The physiological requirement of biotin is diverse within ESKAPE pathogens. CRISPR-Cas9-based inactivation of bioC rendered A. baumannii and K. pneumoniae biotin auxotrophic. The availability of soluble AbBioC enabled the in vitro reconstitution of DTB/biotin synthesis. We solved two crystal structures of AbBioC bound to SAM cofactor (2.54 angstroms) and sinefungin (SIN) inhibitor (1.72 angstroms). Structural and functional study provided molecular basis for SIN inhibition of BioC. We demonstrated that BioC methyltransferase plays dual roles in K. pneumoniae infection and A. baumannii colistin resistance. [ABSTRACT FROM AUTHOR]

The esterase EstSIT01 from Microbacterium can catalyze the asymmetric hydrolysis of meso-dimethyl ester to produce the crucial chiral intermediate (4S, 5R)-hemimethyl ester for d-biotin synthesis. Despite its high yields and stereoselectivity, the low thermostability of EstSIT01 limits its practical application. Herein, two kinds of rational strategies were combined to enhance the thermostability of EstSIT01. Based on the Surface Residue Substitution (SRS) method, two variants (G215A and G316A) with improved thermostability and one mutant (G293A) with superior activity were identified from nine candidates. According to the Consensus Mutation method, two mutants (E301P and A332P) with enhanced thermostability were identified from six candidates. However, the combined mutation failed to yield mutants surpassing the best single mutant, E301P, in terms of thermostability. The combined mutant E301P/G215A and E301P/G215A/G293A exhibited a slight enhancement in enzyme activity relative to E301P, while also exhibiting improved thermostability compared to the wild-type EstSIT01. Compared with the wild-type esterase, the thermal inactivation half-lives (t1/2) of mutant E301P were enhanced 1.4-fold, 2.4-fold and 1.8-fold at 45 °C, 55 °C, and 65 °C, respectively. The optimal reaction temperature and pH for mutant E301P remained consistent with those of the wild type, at 40 °C and 10.0, respectively. The Km of E301P was 0.22 ± 0.03 mM and the kcat was 5.1 ± 0.28 s−1. Further analysis indicated that the free energies of G215A, G293A and E301P were decreased by 0.91, 0.308 and 1.1049 kcal/mol, respectively, compared to the wild-type EstSIT01. The interaction analysis revealed that the substitution of glutamic acid with proline at position 301 enhanced the hydrophobic interactions within the protein. The decreased free energies and the increased hydrophobic interactions were well correlated with the enhanced stability in these mutants. [ABSTRACT FROM AUTHOR]

Background Methods Results Conclusion Production of platelet concentrates (PCs) involves several steps that significantly affect platelet behavior. To gain a deeper understanding of how storage conditions impact donor platelet recirculation and functionality post‐transfusion, ex vivo platelet labeling is a feasible approach. However, before pursuing clinical investigations of platelet recirculation and function in humans, we aimed to determine the effects of pathogen inactivation technology (PIT) and storage conditions (4°C vs. room temperature [RT]) on phenotype and function of biotinylated platelets compared to conventional PIT PCs for transfusion.Nine PCs were prepared in 61% additive solution from 45 buffy coats (five buffy coats each). A pool‐and‐split of three units was used to prepare three equivalent PCs: two labeled with biotin and stored at RT or 4°C, and one without labeling and stored at RT. All PCs were then treated by PIT (amotosalen/UVA) and stored for 14 days. Labeling efficiency, platelet concentration, metabolic parameters, aggregation response (ADP, collagen, co‐aggregation with epinephrine), and platelet phenotype (CD42b, CD62‐P, phosphatidylserine) at the basal stage and upon stimulation (ADP or TRAP‐6) were performed.Labeling efficiency of PIT and 4°C PCs was stable over 14 days of storage. Differences in platelet function and phenotype were mainly due to the storage temperature and not the biotinylation process. Phenotypes at baseline or after stimulation were equivalent in biotin‐positive and biotin‐negative platelets.Biotin‐labeled platelets can effectively enable investigation of the effects of PIT and storage temperature for clinical studies. This method shows great potential for improving platelet transfusion knowledge. [ABSTRACT FROM AUTHOR]

Copyright of Food Research & Development is the property of Food Research & Development Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Introduction: Holocarboxylase synthetase deficiency (HLCSD) is a rare autosomal recessive genetic disorder caused by mutations in the holocarboxylase synthetase (HLCS) gene, which affects multiple systems. Common clinical manifestations include metabolic acidosis, rash, feeding difficulties, and growth retardation, with predominant involvement of the nervous system, skin, and hair. However, respiratory symptoms as the initial manifestation are relatively rare. Case Presentation: We report the case of a 1 year and 4-month-old Chinese male patient who presented with a 2-day history of cough, followed by half a day of wheezing and shortness of breath. Despite supportive treatment with antibiotics upon admission, the infant continued to experience rapid and deep breathing accompanied by groaning, and obvious wheezing. Blood gas analysis revealed metabolic acidosis that was difficult to correct. Blood tandem mass spectrometry showed elevations in C50H, C3, C4OH, and urine organic acid analysis revealed elevations in lactate, 3-hydroxybutyric acid, 3-hydroxyisovaleric acid, acetoacetic acid, 3-methylcrotonylglycine, and methylcitric acid. Genetic testing revealed two variants in the HLCS gene in the infant: NM_001352514: exon6: c.1088T>A: p.V363D variant and exon11: c.2434C>T: p.R812* heterozygous variant, resulting in HLCSD. Ultimately, the diagnosis of HLCSD was established, and oral biotin treatment achieved good clinical efficacy. Conclusion: This article summarizes the clinical data of a case of HLCSD in an infant, primarily presenting with respiratory symptoms. It provides a comprehensive summary of the etiology, diagnosis, and treatment, offering insights for the diagnosis of rare diseases by clinical physicians. [ABSTRACT FROM AUTHOR]

Numerous studies have demonstrated the efficacy of selenium compounds in preventing and treating lifestyle-related diseases such as cancer and cardiovascular disorders. The formulation of selenium-enriched supplements for humans and animals, particularly those containing selenium yeast, is highly advantageous. These products are rich in organic selenium derivatives, showing significantly higher bioavailability than inorganic forms of selenium. A particularly promising selenium analogue of sulphur-containing compounds is selenobiotin. The literature indicates that Phycomyces blakesleeanus and Escherichia coli strains can synthesise this compound. This research aimed to evaluate the effect of selenium supplementation on the biosynthesis of biotin and selenobiotin in Trichosporon cutaneum and Meyerozyma guilliermondii. The results have the potential to advance biotechnological approaches for the production of selenobiotin for various applications. A method based on affinity chromatography was used to quantify selenobiotin. The results confirmed that both yeast strains could synthesise selenobiotin in addition to biotin. In M. guilliermondii cells, selenobiotin accounted for up to 17.3% of the total biotin vitamer fraction. In comparison, in T. cutaneum cells, it accounted for up to 28.4% of the sum of biotin and its analogues. The highest levels of selenobiotin were observed in cells cultured with selenomethionine. [ABSTRACT FROM AUTHOR]

Aim: The etiology of telogen effluvium (TE) includes situations that may cause physiological stress, surgical trauma, inflammatory, infectious, iatrogenic causes, medications and nutritional deficiencies. TE has been associated with iron deficiency, vitamin B12 deficiency and thyroid diseases. In recent years, the use of over‐the‐counter food supplements containing vitamins and minerals such as biotin, vitamin D, zinc (Zn), copper (Cu) and selenium (Se) has been increasing in TE patients. The aim of this study is to investigate whether there are differences in nutritional status, vitamin and mineral levels by comparing individuals with TE and a control group. Materials and Methods: This case–control study included 90 female patients diagnosed with chronic telogen effluvium (CTE), and 90 female controls volunteered to participate in the study who consulted for reasons other than TE. Both groups aged 18 and over and applied to dermatology polyclinic between 01.09.2022 and 01.09.2023. A detailed anamnesis was taken from all patients, a hair pull test was performed, and TE was diagnosed after a dermoscopic examination was performed on all areas of the scalp. Then, serum vitamin D, Zn, Cu, Se levels and biotin levels in serum and urine were measured. Hemoglobin (Hb), ferritin, vitamin B12 and thyroid function tests were retrospectively scanned from the hospital database. Results: It was determined that Zn levels were significantly lower in CTE patients than in controls. Se levels were found to be significantly higher in patients than in controls. There was no difference in Hb, ferritin, vitamin B12, thyroid function tests, vitamin D, Cu levels, serum and urine biotin levels between the two groups. Zn, Cu/Zn and Se levels were found to have statistically significant diagnostic performance in predicting the diagnosis of CTE. Cu/Zn ratio and Se value were found to be significant predictors of CTE. Conclusion: This study shows us that nutritional deficiencies are not as common as thought in patients diagnosed with TE. Other causes that may cause TE should be investigated by a detailed anamnesis and a good physical examination. After all, tests for suspected conditions should be performed and individualized treatment options should be created for each patient. [ABSTRACT FROM AUTHOR]

Propionyl CoA carboxylase (PCC) is a multimeric enzyme composed of two types of subunits, α and β arranged in α6β6 stoichiometry. The α-subunit consists of an N-terminal carboxylase domain, a carboxyl transferase domains, and a C-terminal biotin carboxyl carrier protein domain (BCCP). The β-subunit is made up of an N- and a C- carboxyl transferase domain. During PCC catalysis, the BCCP domain plays a central role by transporting a carboxyl group from the α-subunit to the β-subunit, and finally to propionyl CoA carboxylase, resulting in the formation of methyl malonyl CoA. A point mutation in any of the subunits interferes with multimer assembly and function. Due to the association of this enzyme with propionic acidemia, a genetic metabolic disorder found in humans, PCC has become an enzyme of wide spread interest. Interestingly, unicellular eukaryotes like Leishmania also possess a PCC in their mitochondria that displays high sequence conservation with the human enzyme. Thus, to understand the function of this enzyme at the molecular level, we have initiated studies on Leishmania major PCC (LmPCC). Here we report chemical shift assignments of LmPCC BCCP domain using NMR. Conformational changes in LmPCC BCCP domain upon biotinylation, as well as upon interaction with its cognate biotinylating enzyme (Biotin protein ligase from L. major) have also been reported. Our studies disclose residues important for LmPCC BCCP interaction and function. [ABSTRACT FROM AUTHOR]

Ru(II)-complexes have been recognised as promising in treating cancer. However, targeted delivery is an important facet to augment the efficiency of drugs. Consequently, this article portrays the construction of biotinylated-MWCNTs as an SMVT-guided nano-platform for the precise delivery of our previously-developed potent Ru(II)-scaffold, making it more effective against MCF-7 cells. [ABSTRACT FROM AUTHOR]

Voltage-responsive biosensors capable of monitoring real-time adsorption behavior of biological analytes onto electroactive surfaces offer attractive strategies for disease detection, separations, and other adsorption-dependent analytical techniques. Adsorption of biological analytes onto electrically switchable surfaces can be modelled using neutravidin and biotin. Here, we report self-assembled monolayers formed from voltage-switchable biotinylated molecules on gold surfaces with tunable sensitivity to neutravidin in response to applied voltages. By using electrochemical quartz crystal microbalance (EQCM), we demonstrated real-time switchable behavior of these bio-surfaces and investigate the range of sensitivity by varying the potential of the same surfaces from −400 mV to open circuit potential (+155 mV) to +300 mV. We compared the tunability of the mixed surfaces to bare Au surfaces, voltage inert surfaces, and switchable biotinylated surfaces. Our results indicate that quartz crystal microbalance allows real-time changes in analyte binding behavior, which enabled observing the evolution of neutravidin sensitivity as the applied voltage was shifted. EQCM could in principle be used in kinetic studies or to optimize voltage-switchable surfaces in adsorption-based diagnostics. [ABSTRACT FROM AUTHOR]

The modified Escherichia coli biotin ligase BirA* was the first developed for proximity labeling of proteins (BioID). However, it has low activity at temperatures below 37°C, which reduces its effectiveness in organisms growing at lower temperatures, such as budding yeast. Multiple derivatives of the enzymes have been engineered, but a thorough comparison of these variations of biotin ligases and the development of versatile tools for conducting these experiments in Saccharomyces cerevisiae would benefit the community. Here, we designed a suite of vectors to compare the activities of biotin ligase enzymes in yeast. We found that the newer TurboID versions were the most effective at labeling proteins, but they displayed low constitutive labeling of proteins even in the absence of exogenous biotin, due to biotin contained in the culture medium. We describe a simple strategy to express free BioID enzymes in cells that can be used as an appropriate control in BioID studies to account for the promiscuous labeling of proteins caused by random interactions between bait-BioID enzymes in cells. We also describe chemically induced BioID systems exploiting the rapamycin-stabilized FRB-FKBP interaction. Finally, we used the TurboID version of the enzyme to explore the interactome of different subunits of the Ccr4 -Not gene regulatory complex. We find that Ccr4 -Not predominantly labeled cytoplasmic mRNA regulators, consistent with its function in mRNA decay and translation quality control in this cell compartment. [ABSTRACT FROM AUTHOR]

Holocarboxylase synthase (HCS) deficiency is an extremely rare metabolic disorder typically presenting as severe neonatal metabolic acidosis, lethargy, hypotonia, vomiting, and seizures. This report describes two siblings in a family with late-onset forms of HCS deficiency. The younger sister presented at the age of 11 years and manifested as acute metabolic acidosis, which promptly resolved following rehydration and biotin administration. The results of the organic urine profile confirmed multiple carboxylase deficiency, and genetic testing revealed a novel pathogenic variant in the HLCS gene (NM_000411.8) in the homozygous state: c.995A>G; p. (Gln332Arg). No further decompensation was observed for her during the 3-year follow-up period. His older brother was diagnosed at the age of 23 years-old through biochemical tests, without any history of acidotic decompensation. A mini-review of HCS deficiency with late onset (>1 year) or early onset (<1 month) revealed that splice variants are associated with late onset, while both variants p. (Leu216Arg) and p. (Leu237Pro) are associated with early onset. However, the majority of genotypes do not show a clear correlation with the timing of HCS deficiency onset. The most significant point here is the description of extremely late-onset cases of HCS deficiency. This can prompt metabolic investigations and raise suspicion of this rare disease in cases of unexplained metabolic acidosis, even beyond early childhood. [ABSTRACT FROM AUTHOR]

Biotin (vitamin B7) is a crucial cofactor for various metabolic processes and has significant applications in pharmaceuticals, cosmetics, and animal feed. Bacillus subtilis, a well-studied Gram-positive bacterium, presents a promising host for biotin production due to its Generally Recognized as Safe (GRAS) status, robust genetic tractability, and capacity for metabolite secretion. This study focuses on the metabolic engineering of B. subtilis to enhance biotin biosynthesis. Initially, the desthiobiotin (DTB) and biotin synthesis ability of different B. subtilis strains were evaluated to screen for suitable chassis cells. Subsequently, the titers of DTB and biotin were increased to 21.6 mg/L and 2.7 mg/L, respectively, by relieving the feedback repression of biotin synthesis and deleting the biotin uptake protein YhfU. Finally, through engineering the access tunnel to the active site of biotin synthase (BioB) for reactants and modulating its expression, the biotin titer was increased to 11.2 mg/L, marking an 1130-fold improvement compared to the wild-type strain. These findings provide novel strategies for enhancing the production of DTB and improving the conversion efficiency of DTB to biotin.

Background. Aging is a complex biological process of gradual metabolic, structural and functional changes in the body, which can lead to a decline in physical and mental functions, as well as to the development of diseases. At the moment, the issue of anti-aging remains relevant, given the steady increase in life expectancy and the growing proportion of the elderly population, which is observed practically worldwide. Biologically active supplements containing components used as part of complex therapy for the correction and prevention of signs of premature skin aging are becoming increasingly popular. Aims. To evaluate the effectiveness and safety of taking the dietary supplement VITABEAUTY® Hyaluronic Acid + Resveratrol on the functional parameters of facial skin. Methods. A simple blind placebo-controlled cross-over study was conducted, involving 40 female patients over 18 years old with signs of aging. The observation was carried out for 10 weeks. The dietary supplement and placebo were taken according to the following scheme: during the first 4 weeks of the study patients received placebo, then the subjects took VITABEAUTY® Hyaluronic Acid + Resveratrol for the next 6 weeks. Objective assessment of skin condition was carried out in 4 and 10 weeks after the beginning of the study in strictly fixed areas of the forehead and cheek. The patients’ subjective evaluation of the effectiveness of the supplement VITABEAUTY® Hyaluronic Acid + Resveratrol also was carried out. Results. Statistically significant improvement of skin moisture and wrinkle depth was registered at the end of the study at patiens receiving VITABEAUTY® Hyaluronic Acid + Resveratrol. 95% of the subjects evaluated the result of taking the dietary supplement as good and satisfactory. Conclusion. The obtained results allow us to recommend the dietary supplement VITABEAUTY® Hyaluronic Acid + Resveratrol for regular intake to prevent and/or control the initial signs of skin aging.

Streptavidin affinity grids provide strategies to overcome many commonly encountered cryo-electron microscopy (cryo-EM) sample preparation challenges, including sample denaturation and preferential orientations that can occur due to the air-water interface. Streptavidin affinity grids, however, are currently utilized by few cryo-EM labs because they are not commercially available and require a careful fabrication process. Two-dimensional streptavidin crystals are grown onto a biotinylated lipid monolayer that is applied directly to standard holey-carbon cryo-EM grids. The high-affinity interaction between streptavidin and biotin allows for the subsequent binding of biotinylated samples that are protected from the air-water interface during cryo-EM sample preparation. Additionally, these grids provide a strategy for concentrating samples available in limited quantities and purifying protein complexes of interest directly on the grids. Here, a step-by-step, optimized protocol is provided for the robust fabrication of streptavidin affinity grids for use in cryo-EM and negative-stain experiments. Additionally, a trouble-shooting guide is included for commonly experienced challenges to make the use of streptavidin affinity grids more accessible to the larger cryo-EM community.

Avidin-biotin binding, the most robust non-covalent protein-ligand interaction occurring in nature, has wide-ranging applications in biotechnology. A frequent challenge in these applications is accurately determining the number of unoccupied biotin binding sites in avidin-containing fusion proteins. We delineate a novel assay protocol in miniaturized format to quantify available biotin binding sites based on the affinity of the anionic dye 4′-hydroxyazobenzene-2-carboxylic acid for biotin binding sites within avidin. We apply this assay as a quality control assay to evaluate the number of available biotin binding sites in different fusion protein production batches. This method offers a streamlined alternative to fluorescence-based assays commonly employed to assess biotin binding, is less time-consuming than other methods and is applicable to diverse fusion proteins.

Copyright of Journal of Food Safety & Quality is the property of Journal of Food Safety & Quality Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Objectives Biotin causes negative interference with thyroglobulin measurement using the Access thyroglobulin assay. Recently, Beckman reformulated the thyroglobulin assay to overcome biotin interference. We investigated the effect of biotin on both current and newly formulated assays. Methods Four serum pools were prepared using specimens containing various amounts of thyroglobulin. Then aliquots of each pool were supplemented with various amounts of biotin, and thyroglobulin concentrations were measured by both the current and the new assays. In addition, 3 volunteers ingested 10 mg biotin, and specimens were drawn before and 2 hours after taking biotin. Thyroglobulin concentrations before and 2 hours after taking biotin were measured by both assays. Results In the presence of biotin, thyroglobulin concentrations were reduced significantly using the current assay, but no significant change was observed using the newly formulated assay. We observed similar results in vivo. Conclusions The newly formulated thyroglobulin assay by Beckman is free from biotin interference. [ABSTRACT FROM AUTHOR]

Heading date 3a (Hd3a, a FLOWERING LOCUS T (FT) ortholog from rice) is well known for its important role in rice (Oryza sativa L.), controlling floral transition under short-day (SD) conditions. Although the effect of Hd3a on promoting branching has been found, the underlying mechanism remains largely unknown. In this report, we overexpressed an Hd3a and BirAG (encoding a biotin ligase) fusion gene in rice, and found that early flowering and tiller bud outgrowth was promoted in BHd3aOE transgenic plants. On the contrary, knockout of Hd3a delayed flowering and tiller bud outgrowth. By using the BioID method, we identified multiple Hd3a proximal proteins. Among them, D14, D53, TPR1, TPR2, and TPRs are central components of the strigolactone signaling pathway, which has an inhibitory effect on rice tillering. The interaction between Hd3a, on the one hand, and D14 and D53 was further confirmed by the bimolecular fluorescence complementation (BiFC), yeast two-hybrid (Y2H), and co-immunoprecipitation (Co-IP) methods. We also found that Hd3a prevented the degradation of D53 induced by rac-GR24 (a strigolactone analog) in rice protoplasts. RT-qPCR assay showed that the expression levels of genes involved in strigolactone biosynthesis and signal transduction were altered significantly between WT and Hd3a overexpression (Hd3aOE) or mutant (hd3a) plants. OsFC1, a downstream target of the strigolactone signaling transduction pathway in controlling rice tillering, was downregulated significantly in Hd3aOE plants, whereas it was upregulated in hd3a lines. Collectively, these results indicate that Hd3a promotes tiller bud outgrowth in rice by attenuating the negative effect of strigolactone signaling on tillering and highlight a novel molecular network regulating rice tiller outgrowth by Hd3a. [ABSTRACT FROM AUTHOR]

Streptavidin is a tetrameric protein with high specificity and affinity for biotin. The interaction between avidin and biotin has become a valuable tool in nanotechnology. In recent years, the site‐specific biotin modification of proteins using biotin ligases, such as BirA, has attracted attention. This study established an in vivo method for achieving the complete biotinylation of target proteins using a single plasmid co‐expressing BirA and its target proteins. Specifically, a biotin‐modified protein was produced in Escherichia coli strain BL21(DE3) using a single plasmid containing genes encoding both BirA and a protein fused to BirA's substrate sequence, Avitag. This approach simplifies the production of biotinylated proteins in E. coli and allows the creation of various biotinylated protein types through gene replacement. Furthermore, the biotin modification rate of the obtained target protein could be evaluated using Native‐PAGE without performing complicated isolation operations of biotinylated proteins. In Native‐PAGE, biotin‐modified proteins and unmodified proteins were confirmed as clearly different bands, and it was possible to easily derive the modification rate from the respective band intensities. [ABSTRACT FROM AUTHOR]

This work implements a method for specific in vivo biotinylation of recombinant proteins M1 and B7 of the variola virus during biosynthesis in CHO-K1 cells. To do this, co-expression of the biotin ligase BirA and target genes encoding the ectodomains of the M1 and B7 proteins with a C-terminal avi-tag was carried out in CHO-K1 cells in the presence of biotin in the culture medium. The optimal biotin concentration for the expression of the M1 and B7 proteins was 125 μM. The production of biotinylated recombinant proteins has been complicated by low yields. To increase the production of target proteins, low molecular weight enhancers were added to the culture medium: lithium acetate, sodium valproate, and caffeine. The enhancers increased the yield of the target protein by 1.3–4.9 times and did not affect the efficiency of biotinylation. The highest yield of biotinylated protein was achieved with the simultaneous addition of a concentration of 10 mM lithium acetate and 2.5 mM sodium valproate. [ABSTRACT FROM AUTHOR]

The list of standard abbreviations for JDS is available at adsa.org/jds-abbreviations-24. Nonstandard abbreviations are available in the Notes. Our objectives were to develop and evaluate an integrated system consisting of a lateral flow immunoassay (LFIA) and an electronic portable imaging device for determination of pregnancy status of cows based on plasma concentrations of pregnancy-specific protein B (PSPB). Experiment 1 was conducted to test the performance of the LFIA for PSPB (PSPB-LFIA), whereas experiment 2 was conducted to evaluate the performance of the integrated system, including both the LFIA and imaging device. The PSPB-LFIA strips were made of nitrocellulose membrane with polystreptavidin, anti-mouse antibody, europium anti-PSPB conjugates, and biotin PSPB. After adding buffer and plasma in a 96-well plate, strips were dipped to initiate flow and were read in a fluorescence microscope to estimate PSPB concentrations based on the test-to-control line signal (T/C ratio). The T/C ratio of standards was linearly associated with PSPB (R2 = 0.99 in both experiments) concentrations. To test the ability to identify pregnant cows of the PSPB-LFIA only or the integrated system, plasma samples were collected and transrectal ultrasonography (TUS) was conducted 29 to 35 d after AI in lactating Holstein cows (experiment 1: n = 83; experiment 2: n = 205). A cow was considered pregnant (Preg) if concentrations of PSPB in plasma obtained by ELISA were ≥2 ng/mL or if an embryo was visible by TUS. In experiment 1, the accuracy of the PSPB-LFIA compared with ELISA was 92.7% (91.2% sensitivity [Se]; 96.1% specificity [Sp]; 98.1% positive predictive value [PPV]; 83.3% negative predictive value [NPV]) and compared with TUS was 90.4% (100% Se; 78.9% Sp; 84.9% PPV; 100% NPV). The agreement between LFIA and ELISA (kappa = 0.84; 95% CI 0.71–0.96) or LFIA and TUS (kappa = 0.80; 95% CI 0.67–0.93) as methods to classify cows as Preg or nonpregnant (Non-Preg) was high. In experiment 2, the accuracy of the PSPB-LFIA compared with ELISA was 96.1% (93.8% Se; 100% Sp; 100% PPV; 90.5% NPV) and compared with TUS was 92.2% (99.0% Se; 84.7% Sp; 87.6% PPV; 98.8% NPV). The agreement between LFIA and ELISA (kappa = 0.92; 95% CI 0.86–0.97) or LFIA and TUS (kappa = 0.84; 95% CI 0.77–0.92) as methods to classify cows as Preg or Non-Preg was high. We conclude that a system integrating a fluorescence-based LFIA and an optical reader was effective for classifying cows as pregnant or not pregnant based on estimations of plasma concentrations of PSPB. This novel system serves as a platform for further development of on-farm pregnancy testing tools based on measurement of biomarkers of pregnancy in bodily fluids of cattle. [ABSTRACT FROM AUTHOR]

Biotin is essential for metabolizing the three major nutrients and is vital for animal growth and development. Industrially, biotin production has relied on chemical synthesis, a method fraught with disadvantages including complex processes, environmental risks, and high costs. Consequently, researchers have increasingly recognized the benefits of biosynthesizing biotin. Native transcriptional regulation and metabolic bottlenecks restrict biotin production. Replacing the native promoter and bioO with the constitutive P 43 promoter, along with swapping the native birA for a non-regulatory variant from Mycobacterium tuberculosis , significantly upregulated biotin biosynthetic gene expression, effectively bypassing native transcriptional regulation. Subsequent strategies to bypass the inefficient native BioW included knocking out ydbM in the β-oxidation pathway—a potential pimeloyl-CoA degrader, expressing heterologous bioW genes, and introducing alternative pimeloyl-ACP biosynthetic pathways, collectively increasing biotin titers to 6.91 mg/L. This study demonstrates a multi-faceted approach to overcoming metabolic and regulatory barriers, providing a template for enhancing biotin production in B. subtilis , with implications for the broader field of microbial biotechnology. [Display omitted] • Effective bypass of transcriptional repression mechanism of biotin. • Screening of heterologous bioW genes to bypass the inefficient native BioW. • Incorporation of pimeloyl-ACP biosynthetic pathways to bypass the inefficient native BioW. [ABSTRACT FROM AUTHOR]

Microfluidics has emerged as a highly promising technology for miniaturizing chemical analysis laboratory into a single, small lab-on-a-chip device. In our previous research, we have developed an innovative approach to particle-based microfluidics by screen printing silica gel microparticles onto glass substrate to create a patterned porous material. In this article we demonstrate a multi-step sample analysis – combining conventional and affinity thin-layer chromatography with competitive assay for detection – along with blister reservoirs that can be integrated into the particle-based microfluidic point-of-care test. This integration achieves high analytical performance and makes the test simple to use. Biotin was chosen as the exemplary analyte, because measuring it is crucial in immunoassays, where high circulating biotin concentrations can lead to false results. This research also addresses the challenge of biotin interference in immunoassays by making it possible to produce rapid biotin tests. Need for these tests is particularly critical in emergency situations. Validation of the developed test demonstrated a dynamic range of 0.09 to 0.24 µg ml− 1 and that artificial urine matrix does not have significant effect on the results. This would make it possible to assess whether the biotin interference occurs in urine sample immunoassays. [ABSTRACT FROM AUTHOR]

Introduction: Phages are viruses that infect prokaryotes and can shape microbial communities by lysis, thus offering applications in various fields. However, challenges exist in sampling, isolation and accurate prediction of the host specificity of phages as well as in the identification of newly replicated virions in response to environmental challenges. Methods: A new workflow using biorthogonal non-canonical amino acid tagging (BONCAT) and click chemistry (CC) allowed the combined analysis of phages and their hosts, the identification of newly replicated virions, and the specific tagging of phages with biotin for affinity chromatography. Results: Replication of phage λ in Escherichia coli was selected as a model for workflow development. Specific labeling of phage λ proteins with the non-canonical amino acid 4-azido-L-homoalanine (AHA) during phage development in E. coli was confirmed by LC-MS/MS. Subsequent tagging of AHA with fluorescent dyes via CC allowed the visualization of phages adsorbed to the cell surface by fluorescence microscopy. Flow cytometry enabled the automated detection of these fluorescent phage-host complexes. Alternatively, AHA-labeled phages were tagged with biotin for purification by affinity chromatography. Despite biotinylation the tagged phages could be purified and were infectious after purification. Discussion: Applying this approach to environmental samples would enable host screening without cultivation. A flexible and powerful workflow for the detection and enrichment of phages and their hosts in pure cultures has been established. The developed method lays the groundwork for future workflows that could enable the isolation of phage-host complexes from diverse complex microbial communities using fluorescence-activated cell sorting or biotin purification. The ability to expand and customize the workflow through the growing range of compounds for CC offers the potential to develop a versatile toolbox in phage research. This work provides a starting point for these further studies by providing a comprehensive standard operating procedure. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: DNA 5‐formylcytosine (5fC) is a prominent epigenetic modification within biological systems. Recent investigations have shed light on its pivotal role in governing cell fate, gene expression, and disease pathways. However, our comprehension of the precise control of the 5fC site structure to influence its functionality remains limited. In this study, we have successfully achieved precise control over 5fC activity by harnessing the interaction between streptavidin and biotin. This research underscores the potential application of interactions between biomacromolecules and small molecules in advancing the field of DNA epigenetic functional regulation. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: DNA 5‐formylcytosine (5fC) is a prominent epigenetic modification within biological systems. Recent investigations have shed light on its pivotal role in governing cell fate, gene expression, and disease pathways. However, our comprehension of the precise control of the 5fC site structure to influence its functionality remains limited. In this study, we have successfully achieved precise control over 5fC activity by harnessing the interaction between streptavidin and biotin. This research underscores the potential application of interactions between biomacromolecules and small molecules in advancing the field of DNA epigenetic functional regulation. [ABSTRACT FROM AUTHOR]

A novel, industrially viable synthetic route to (+)‐biotin has been developed starting from L‐cysteine via the known key thiolactone intermediate. The route takes advantage of the in‐built stereochemistry of the cysteine starting material and the best features of the two current industrialized processes. The key transformations are the conversion of L‐cysteine into a hydantoin avoiding racemization followed by catalytic cyanation and thiolactonization to form the required thiolactone intermediate. This known intermediate can be readily further transformed into (+)‐biotin. [ABSTRACT FROM AUTHOR]

Rad6 is a canonical ubiquitin-conjugating enzyme known for its role in regulating chromosome-related cellular processes in yeast and has been proven to have multiple functions in Beauveria bassiana, including insect-pathogenic lifestyle, UV damage repair, and conidiation. However, previous studies have only reported the key role of Rad6 in regulating conidial production in a nutrient-rich medium, without any deep mechanism analyses. In this study, we found that the disruption of Rad6 leads to a profound reduction in conidial production, irrespective of whether the fungus is cultivated in nutrient-rich or nutrient-poor environments. The absence of rad6 exerts a suppressive effect on the transcription of essential genes in the central developmental pathway, namely, brlA, abaA, and wetA, resulting in a direct downregulation of conidiation capacity. Additionally, mutant strains exhibited a more pronounced decline in both conidial generation and hyphal development when cultured in nutrient-rich conditions. This observation correlates with the downregulation of the central developmental pathway (CDP) downstream gene vosA and the upregulation of flaA in nutrient-rich cultures. Moreover, single-transcriptomics analyses indicated that irregularities in biotin metabolism, DNA repair, and tryptophan metabolism are the underlying factors contributing to the reduced conidial production. Comprehensive dual transcriptomics analyses pinpointed abnormal biotin metabolism as the primary cause of conidial production decline. Subsequently, we successfully restored conidial production in the Rad6 mutant strain through the supplementation of biotin, further confirming the transcriptomic evidence. Altogether, our findings underscore the pivotal role of Rad6 in influencing biotin metabolism, subsequently impacting the expression of CDP genes and ultimately shaping the asexual life cycle of B. bassiana. [ABSTRACT FROM AUTHOR]

Mild-to-moderate ulcerative colitis (UC) management is centred on 5-aminosalicylic acid (5-ASA) derivatives. Whether supplementing 5-ASA with nutraceuticals can provide real advantages in UC-relevant outcomes is unclear. This retrospective multicentre study compared clinical remission, response rates, and faecal calprotectin levels in a two-arm design, including patients treated with 5-ASA alone and those with additional H. erinaceus-based multi-compound supplementation. In the 5-ASA alone group, clinical response rates were 41% at three months (T1) and 60.2% at six months (T2), while corresponding clinical remission rates were 16.9% and 36.1%. In the nutraceutical supplementation group, clinical response rates were 49.6% (T1) and 70.4% (T2), with clinical remission rates of 30.4% (T1) and 50.9% (T2). No significant differences in clinical response rates between the groups at T1 (p = 0.231) and T2 (p = 0.143) emerged. Clinical remission rates differed significantly at both time points (p = 0.029 and p = 0.042, respectively). Faecal calprotectin levels decreased significantly in both groups during the retrospective follow-up (p < 0.05), and this was more pronounced in nutraceutical supplementation patients at both T1 (p = 0.005) and T2 (p = 0.01). No adverse events were reported. This multi-component nutraceutical supplementation offers real-world potential in controlling disease activity in patients with mild-to-moderate UC. [ABSTRACT FROM AUTHOR]

A series of biotin-functionalized transition metal complexes was prepared by iClick reaction from the corresponding azido complexes with a novel alkyne-functionalized biotin derivative ([Au(triazolatoR,R′)(PPh3)], [Pt(dpb)(triazolatoR,R′)], [Pt(triazolatoR,R′)(terpy)]PF6, and [Ir(ppy)(triazolatoR,R′)(terpy)]PF6 with dpb = 1,3-di(2-pyridyl)benzene, ppy = 2-phenylpyridine, and terpy = 2,2′:6′,2′′-terpyridine and R = C6H5, R′ = biotin). The complexes were compared to reference compounds lacking the biotin moiety. The binding affinity toward avidin and streptavidin was evaluated with the HABA assay as well as isothermal titration calorimetry (ITC). All compounds exhibit the same binding stoichiometry of complex-to-avidin of 4:1, but the ITC results show that the octahedral Ir(III) compound exhibits a higher binding affinity than the square-planar Pt(II) complex. The antibacterial activity of the compounds was evaluated on a series of Gram-negative and Gram-positive bacterial strains. In particular, the neutral Au(I) and Pt(II) complexes showed significant antibacterial activity against Staphylococcus aureus and Enterococcus faecium at very low micromolar concentrations. The cytotoxicity against a range of eukaryotic cell lines was studied and revealed that the octahedral Ir(III) complex was non-toxic, while the square-planar Pt(II) and linear Au(I) complexes displayed non-selective micromolar activity. [ABSTRACT FROM AUTHOR]

Background. Biotin is a water-soluble vitamin that plays a key role in carboxylation. The formation of free biotin is impaired in biotinidase deficiency (BD), resulting in impaired biotin-dependent carboxylase functions. Based on the percentage of residual serum enzyme activity, BD is classified as partial and profound. Methods. Retrospective data including gender, age, parental consanguinity, family history, biotinidase activity analyses, type of deficiency (partial-profound), physical examination, treatment, and genotypes were evaluated in patients diagnosed with biotinidase deficiency in a single center in the eastern region of Türkiye. Patients whose biotinidase enzyme activity was below 30% with biallelic variants in the BTD gene were diagnosed as BD. Results. A total of 302 patients were included in the study. Parental consanguinity was present in 135 (44.7%) of them. Two hundred eighty-six (94.7%) were diagnosed by neonatal screening, 14 (4.6%) by family screening and two (0.06%) by clinical symptoms. Ninety-two (30.5%) of the patients were followed-up with profound deficiency and 210 (69.5%) with partial deficiency. A total of 306 variants were detected. Twenty different variants (3 novel - 3 rare) and 31 different genotypes were detected. The 3 most frequently detected variants were c.410G>A (p.Arg137His; 47.3%), c.1270G>C (p.Asp424His; 29.7%), and c.38_44delGCGGCTGinsTCC (p.Cys13Phefs*36; 15.3%). The 3 most frequently identified genotypes were c.410G>A (p.Arg137His) / c.1270G>C (p.Asp424His) compound heterozygous (32.4%), c.410G>A (p.Arg137His) homozygous (24.8%), and c.38_44delGCGGCTGinsTCC (p.Cys13Phefs*36) / c.1270G>C (p.Asp424His) compound heterozygous (12.2%). Patients with c.410G>A (p.Arg137His) homozygous variant, c.38_44delGCGGCTGinsTCC (p.Cys13Phefs*36) homozygous variant and c.38_44delGCGGCTGinsTCC (p.Cys13Phefs*36) / c.410G>A (p.Arg137His) compound heterozygous variant were statistically significantly associated with profound deficiency. Compound heterozygosity of c.410G>A (p.Arg137His) / c.1270G>C (p.Asp424His) variants were significantly associated with partial deficiency. Conclusions. The association between the BTD genotype and biochemical phenotype is not always consistent. Our study provides valuable data by adding variants with genotype-phenotype correlations to the literature and three novel variants, which can provide significant guidance in clinical follow-up. [ABSTRACT FROM AUTHOR]

A spectrophotometric approach that is straightforward, efficient, highly sensitive, and precise has been devised for quantifying biotin in both its pure state and pharmaceutical samples. Analysis of biotin in biological and pharmaceutical samples is essential for therapeutic evaluation and patient follow-up bioavailability. Several methods for determining this drug have drawbacks including specialized equipment that many quality control laboratories and universities in developing countries lack. The methodology relies on the inhibitory approach of biotin on the Pd(II) promoted ligand substitution (LS) reaction involving phenylhydrazine (PHZ) and hexacyanoferrate(II). The process entails replacing cyanide in [Fe(CN)6]4- with PHZ, triggering the development of a complex [Fe(CN)5PHZ]3-. The complex demonstrates a significant level of absorption at a specific wavelength of 488 nm. The established limit of detection for biotin is 0.117 μg mL−1. Experiments on recovery are conducted to confirm the precision and accuracy of biotin quantification. The suggested approach has been effectively utilized for the examination of biotin in pristine samples and various medications, demonstrating remarkable levels of precision and accuracy. The outcomes show good agreement when compared to the findings of the official analytical method. The excipients typically employed in medicines do not exhibit any interference with the suggested methodology. This methodology is highly effective for accurately determining trace levels of different drugs and biological molecules that can significantly impede the catalytic efficiency of Pd(II). [ABSTRACT FROM AUTHOR]

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Numerous studies indicate that intrauterine growth restriction (IUGR) can predispose individuals to metabolic syndrome (MetS) in adulthood. Several reports have demonstrated that pharmacological concentrations of biotin have therapeutic effects on MetS. The present study investigated the beneficial effects of prenatal biotin supplementation in a rat model of intrauterine caloric restriction to prevent cardiometabolic risk in adult female offspring fed fructose after weaning. Female rats were exposed to a control (C) diet or global caloric restriction (20%) (GCR), with biotin (GCRB) supplementation (2 mg/kg) during pregnancy. Female offspring were exposed to 20% fructose (F) in drinking water for 16 weeks after weaning (C, C/F, GCR/F, and GCRB/F). The study assessed various metabolic parameters including Lee's index, body weight, feed conversion ratio, caloric intake, glucose tolerance, insulin resistance, lipid profile, hepatic triglycerides, blood pressure, and arterial vasoconstriction. Results showed that GCR and GCRB dams had reduced weights compared to C dams. Offspring of GCRB/F and GCR/F dams had lower body weight and Lee's index than C/F offspring. Maternal biotin supplementation in the GCRB/F group significantly mitigated the adverse effects of fructose intake, including hypertriglyceridemia, hypercholesterolemia, hepatic steatosis, glucose and insulin resistance, hypertension, and arterial hyperresponsiveness. This study concludes that prenatal biotin supplementation can protect against cardiometabolic risk in adult female offspring exposed to postnatal fructose, highlighting its potential therapeutic benefits. [ABSTRACT FROM AUTHOR]