-
Nutrition Reviews Aug 2008Histones H2A, H3, and H4 are modified by covalent binding of the vitamin biotin to distinct lysine residues. Binding of biotin to histones is mediated by holocarboxylase... (Review)
Review
Histones H2A, H3, and H4 are modified by covalent binding of the vitamin biotin to distinct lysine residues. Binding of biotin to histones is mediated by holocarboxylase synthetase (HCS) and perhaps biotinidase. Biotinylation of lysine- 12 in histone H4 (K12BioH4) plays roles in gene repression, stability of repeat regions and transposable elements, and regulation of biotin transporter expression in eukaryotes. Decreased biotinylation of histones in biotin-deficient and HCS-deficient human cells and impairs stress resistance, life span, and biotin homeostasis.
Topics: Animals; Biotin; Biotinylation; Carbon-Nitrogen Ligases; Chromatin; Dietary Supplements; Epigenesis, Genetic; Female; Histones; Humans; Pregnancy
PubMed: 18673490
DOI: 10.1111/j.1753-4887.2008.00073.x -
Clinical Chemistry and Laboratory... May 2017Immunoassays are now commonly used for hormone measurement, in high throughput analytical platforms. Immunoassays are generally robust to interference. However,... (Review)
Review
Immunoassays are now commonly used for hormone measurement, in high throughput analytical platforms. Immunoassays are generally robust to interference. However, endogenous analytical error may occur in some patients; this may be encountered in biotin supplementation or in the presence of anti-streptavidin antibody, in immunoassays involving streptavidin-biotin interaction. In these cases, the interference may induce both false positive and false negative results, and simulate a seemingly coherent hormonal profile. It is to be feared that this type of errors will be more frequently observed. This review underlines the importance of keeping close interactions between biologists and clinicians to be able to correlate the hormonal assay results with the clinical picture.
Topics: Biotin; False Negative Reactions; False Positive Reactions; Humans; Hyperthyroidism; Immunoassay; Streptavidin
PubMed: 27732554
DOI: 10.1515/cclm-2016-0606 -
ChemistryOpen Jun 2020The synthetic function-spacer-lipid (FSL) amphiphile biotin-CMG-DOPE is widely used for delicate ligation of living cells with biotin residues under physiological...
The synthetic function-spacer-lipid (FSL) amphiphile biotin-CMG-DOPE is widely used for delicate ligation of living cells with biotin residues under physiological conditions. Since this molecule has an "apolar-polar-hydrophobic" gemini structure, the supramolecular organization is expected to differ significantly from the classical micelle. Its organization is investigated with experimental methods and molecular dynamics simulations (MDS). Although the linear length of a single biotin-CMG-DOPE molecule is 9.5 nm, the size of the dominant supramer globule is only 14.6 nm. Investigations found that while the DOPE tails form a hydrophobic core, the polar CMG spacer folds back upon itself and predominantly places the biotin reside inside the globule or planar layer. MDS demonstrates that <10 % of biotin residues on the highly water dispersible globules and only 1 % of biotin residues in layer coatings are in an linear conformation and exposing biotin into the aqueous medium. This explains why in biotin-CMG-DOPE apolar biotin residues both in water dispersible globules and coatings on solid surfaces are still capable of interacting with streptavidin.
Topics: Biotin; Hydrophobic and Hydrophilic Interactions; Molecular Dynamics Simulation; Phosphatidylethanolamines; Protein Conformation; Streptavidin; Surface Properties
PubMed: 32499990
DOI: 10.1002/open.201900276 -
Scientific Reports Dec 2016The strong interaction between streptavidin (SA) and biotin is widely utilized in biotechnological applications. A SA variant, monovalent SA, was developed with a single...
The strong interaction between streptavidin (SA) and biotin is widely utilized in biotechnological applications. A SA variant, monovalent SA, was developed with a single and high affinity biotin-binding site within the intact tetramer. However, its structural characterization remains undetermined. Here, we seek to determine the crystal structure of monovalent SA at 1.7-Å resolution. We show that, in contrast to its 'close-state' in the only wild-type subunit, the L3,4 loops of three Dead SA subunits are free from crystal packing and remain in an 'open state', stabilized by a consistent H-bonding network involving S52. This H-bonding network also applies to the previously reported open state of the wild-type apo-SA. These results suggest that specific substitutions (N23A/S27D/S45A) at biotin-binding sites stabilize the open state of SA L3,4 loop, thereby further reducing biotin-binding affinity. The general features of the 'open state' SA among different SA variants may facilitate its rational design. The structural information of monovalent SA will be valuable for its applications across a wide range of biotechnological areas.
Topics: Binding Sites; Biotin; Crystallography, X-Ray; Models, Molecular; Protein Conformation; Streptavidin; Streptomyces
PubMed: 28000673
DOI: 10.1038/srep35915 -
Cytotherapy Jul 2019Red blood cells (RBCs) can be labeled with N-hydroxysuccinimidobiotin (sulfo-NHS-biotin), which binds to cell surface proteins under aqueous conditions. Biotinylated...
BACKGROUND
Red blood cells (RBCs) can be labeled with N-hydroxysuccinimidobiotin (sulfo-NHS-biotin), which binds to cell surface proteins under aqueous conditions. Biotinylated RBCs can be safely infused and detected in peripheral blood samples using flow cytometry, using a fluorochrome-conjugated streptavidin (SA) detection reagent. Biotinylated RBCs have been used to track survival of transfused RBCs, and have applications in optimizing RBC storage and in understanding donor genetic, environmental and disease factors affecting RBC products.
METHODS
We have developed a closed-system, current good manufacturing practices (cGMP)-compliant procedure for biotinylation of RBCs and a quantitative flow cytometric assay to estimate the dose of cell-bound biotin delivered to the patient. Resulting products were characterized for variability, sterility, endotoxin, hemolysis, total dose of cell-bound biotin and stability.
RESULTS
The density of biotin-labeling increased as a log-linear function of sulfo-NHS-biotin-labeling concentration, with greater variability at lower concentrations. The upper estimates of biotin doses in the average product (mean RBC content = 5.55 × 10) were 9.8 and 73.0 µg for products labeled at 3 and 15 µg sulfo-NHS-biotin/mL of total reaction mixture (27 and 135 nmol/mL packed RBCs), respectively. All products were negative for bacterial and fungal growth at 14 days and were below the limit of endotoxin detection. Biotinylated RBCs were stable in vitro for up to 50 days after labeling.
DISCUSSION
We have validated a closed-system procedure for biotinylating RBCs for investigational use. A standard operating procedure is presented in sufficient detail for implementation in a cGMP-compliant cell-processing facility.
Topics: Biotin; Biotinylation; Erythrocyte Transfusion; Erythrocytes; Flow Cytometry; Fluorescent Dyes; Hemolysis; Humans; Streptavidin; Succinimides
PubMed: 31097327
DOI: 10.1016/j.jcyt.2019.04.052 -
Plant Signaling & Behavior Dec 2012In plants, peroxisomes are the organelles involved in various metabolic processes and physiological functions including β-oxidation, mobilization of seed storage... (Review)
Review
In plants, peroxisomes are the organelles involved in various metabolic processes and physiological functions including β-oxidation, mobilization of seed storage lipids, photorespiration, and hormone biosynthesis. We have recently shown that, in fungi and plants, peroxisomes play a vital role in biosynthesis of biotin, an essential cofactor required for various carboxylation and decarboxylation reactions. In fungi, the mutants defective in peroxisomal protein import exhibit biotin auxotrophy. The fungal BioF protein, a 7-keto-8-aminopelargonic acid (KAPA) synthase catalyzing the conversion of pimeloyl-CoA to KAPA in biotin biosynthesis, contains the peroxisomal targeting sequence 1 (PTS1), and its peroxisomal targeting is required for biotin biosynthesis. In plants, biotin biosynthesis is essential for embryo development. We have shown that the peroxisomal targeting sequences of the BioF proteins are conserved throughout the plant kingdom, and the Arabidopsis thaliana BioF protein is indeed localized in peroxisomes. Our findings suggest that peroxisomal localization of the BioF protein is evolutionarily conserved among eukaryotes, and required for biotin biosynthesis and plant growth and development.
Topics: Biotin; Fungi; Mitochondria; Peroxisomes
PubMed: 23073000
DOI: 10.4161/psb.22405 -
Proteomics Oct 2016Proximity-dependent biotin identification (BioID) is a recently developed method that allows the identification of proteins in the close vicinity of a protein of... (Review)
Review
Proximity-dependent biotin identification (BioID) is a recently developed method that allows the identification of proteins in the close vicinity of a protein of interest in living cells. BioID relies on fusion of the protein of interest with a mutant form of the biotin ligase enzyme BirA (BirA*) that is capable of promiscuously biotinylating proximal proteins irrespective of whether these interact directly or indirectly with the fusion protein or are merely located in the same subcellular neighborhood. The covalent addition of biotin allows the labeled proteins to be purified from cell extracts on the basis of their affinity for streptavidin and identified by mass spectrometry. To date, BioID has been successfully applied to study a variety of proteins and processes in mammalian cells and unicellular eukaryotes and has been shown to be particularly suited to the study of insoluble or inaccessible cellular structures and for detecting weak or transient protein associations. Here, we provide an introduction to BioID, together with a detailed summary of where and how the method has been applied to date, and briefly discuss technical aspects involved in the planning and execution of a BioID study.
Topics: Animals; Biotin; Biotinylation; Humans; Protein Binding; Protein Interaction Mapping
PubMed: 27329485
DOI: 10.1002/pmic.201600123 -
Metabolic Engineering Jul 2020Biotin, thiamine, and lipoic acid are industrially important molecules naturally synthesized by microorganisms via biosynthetic pathways requiring iron-sulfur (FeS)...
Biotin, thiamine, and lipoic acid are industrially important molecules naturally synthesized by microorganisms via biosynthetic pathways requiring iron-sulfur (FeS) clusters. Current production is exclusively by chemistry because pathway complexity hinders development of fermentation processes. For biotin, the main bottleneck is biotin synthase, BioB, a S-adenosyl methionine-dependent radical enzyme that converts dethiobiotin (DTB) to biotin. BioB overexpression is toxic, though the mechanism remains unclear. We identified single mutations in the global regulator IscR that substantially improve cellular tolerance to BioB overexpression, increasing Escherichia coli DTB-to-biotin biocatalysis by more than 2.2-fold. Based on proteomics and targeted overexpression of FeS-cluster biosynthesis genes, FeS-cluster depletion is the main reason for toxicity. We demonstrate that IscR mutations significantly affect cell viability and improve cell factories for de novo biosynthesis of thiamine by 1.3-fold and lipoic acid by 1.8-fold. We illuminate a novel engineering target for enhancing biosynthesis of complex FeS-cluster-dependent molecules, paving the way for industrial fermentation processes.
Topics: Biotin; Escherichia coli; Escherichia coli Proteins; Fermentation; Iron-Sulfur Proteins; Metabolic Engineering; Models, Molecular; Proteomics; Sulfurtransferases; Thiamine; Thioctic Acid; Transcription Factors
PubMed: 32220614
DOI: 10.1016/j.ymben.2020.03.005 -
Journal of Clinical Laboratory Analysis Sep 2021Reports of false laboratory findings due to a biotin supplementation have raised concerns about the safety of immunoassays. According to current research, biotin is...
BACKGROUND
Reports of false laboratory findings due to a biotin supplementation have raised concerns about the safety of immunoassays. According to current research, biotin is known to cause interference in immunoassays. Since up to 70% of medical decisions are based on laboratory results and the significantly increased intake of biotin supplements in the recent years, the reliability of immunoassays is essential.
METHODS
To evaluate this reliability two experiments were conducted. In the first experiment 59 interference suppressed immunoassays of the manufacturer Roche Diagnostics were examined regarding their sensitivity to a biotin interference. In the second experiment the pharmacokinetic of biotin was examined by supplementing volunteers with biotin.
RESULTS
A combination of the results of both experiments suggests that a biotin interference in laboratory findings is probable. Contrary to the current state of research on sandwich immunoassays, falsely elevated test results occur more frequently than falsely low results.
CONCLUSION
The interference suppressed immunoassays have shown in the experiment that they are susceptible to a biotin interference. Therefore, laboratory institutions, medical staff and patients must be aware of the possibility of a biotin interference. As a result, Roche Diagnostics may consider reviewing the interference suppression and their indications of the tests.
Topics: Artifacts; Biotin; Diagnostic Errors; Healthy Volunteers; Humans; Immunoassay; Thyroid Function Tests; Thyroid Hormones
PubMed: 34346119
DOI: 10.1002/jcla.23940 -
Analytical and Bioanalytical Chemistry Jan 2022This study reports the development of a sensitive magnetic bead-based enzyme-linked immunoassay (MELISA) for the pan-reactive detection of the Influenza A virus. The...
This study reports the development of a sensitive magnetic bead-based enzyme-linked immunoassay (MELISA) for the pan-reactive detection of the Influenza A virus. The assay combines immunomagnetic beads and biotin-nanoparticle-based detection to quantify a highly conserved viral nucleoprotein in virus lysates. At the capture step, monoclonal antibody-coated magnetic microbeads were used to bind and concentrate the nucleoprotein in samples. The colorimetric detection signal was amplified using biotinylated silica nanoparticles (NP). These nanoparticles were functionalized on the surface with short DNA spacers bearing biotin groups by an automated supported synthesis method performed on nano-on-micro assemblies with a DNA/RNA synthesizer. A biotin-nanoparticle and immunomagnetic bead-based assay was developed. We succeeded in detecting Influenza A viruses directly in the lysis buffer supplemented with 10% saliva to simulate the clinical context. The biotin-nanoparticle amplification step enabled detection limits as low as 3 × 10 PFU mL and 4 × 10 PFU mL to be achieved for the H1N1 and H3N2 strains respectively. In contrast, a classical ELISA test based on the same antibody sandwich showed detection limit of 1.2 × 10 PFU mL for H1N1. The new enhanced MELISA proved to be specific, as no cross-reactivity was found with a porcine respiratory virus (PRRSV). Graphical abstract.
Topics: Antibodies, Monoclonal; Biotin; Immunomagnetic Separation; Influenza A virus; Nanoparticles; Sensitivity and Specificity
PubMed: 33230699
DOI: 10.1007/s00216-020-03081-x