| Modulation of the reactivity of the thiol of human serum albumin and its sulfenic derivative by fatty acids. | |
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MedLine Citation:
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PMID: 22450170 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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The single cysteine residue of human serum albumin (HSA-SH) is the most abundant plasma thiol. HSA transports fatty acids (FA), a cargo that increases under conditions of diabetes, exercise or adrenergic stimulation. The stearic acid-HSA (5/1) complex reacted sixfold faster than FA-free HSA at pH 7.4 with the disulfide 5,5'-dithiobis(2-nitrobenzoic acid) (DTNB) and twofold faster with hydrogen peroxide and peroxynitrite. The apparent pK(a) of HSA-SH decreased from 7.9±0.1 to 7.4±0.1. Exposure to H(2)O(2) (2mM, 5min, 37°C) yielded 0.29±0.04mol of sulfenic acid (HSA-SOH) per mole of FA-bound HSA. The reactivity of HSA-SOH with low molecular weight thiols increased ∼threefold in the presence of FA. The enhanced reactivity of the albumin thiol at neutral pH upon FA binding can be rationalized by considering that the corresponding conformational changes that increase thiol exposure both increase the availability of the thiolate due to a lower apparent pK(a) and also loosen steric constraints for reactions. Since situations that increase circulating FA are associated with oxidative stress, this increased reactivity of HSA-SH could assist in oxidant removal. |
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Authors:
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María José Torres; Lucía Turell; Horacio Botti; Laura Antmann; Sebastián Carballal; Gerardo Ferrer-Sueta; Rafael Radi; Beatriz Alvarez |
Publication Detail:
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Type: In Vitro; Journal Article; Research Support, N.I.H., Extramural; Research Support, Non-U.S. Gov't Date: 2012-03-19 |
Journal Detail:
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Title: Archives of biochemistry and biophysics Volume: 521 ISSN: 1096-0384 ISO Abbreviation: Arch. Biochem. Biophys. Publication Date: 2012 May |
Date Detail:
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Created Date: 2012-05-04 Completed Date: 2012-06-22 Revised Date: 2013-05-03 |
Medline Journal Info:
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Nlm Unique ID: 0372430 Medline TA: Arch Biochem Biophys Country: United States |
Other Details:
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Languages: eng Pagination: 102-10 Citation Subset: IM |
Copyright Information:
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Copyright © 2012 Elsevier Inc. All rights reserved. |
Affiliation:
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Laboratorio de Enzimología, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay. |
Export Citation:
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APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
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Crystallography, X-Ray Dithionitrobenzoic Acid / metabolism, pharmacology Fatty Acids / metabolism, pharmacology* Humans Hydrogen Peroxide / metabolism, pharmacology Hydrogen-Ion Concentration Models, Molecular Oxidation-Reduction Protein Binding Protein Stability Serum Albumin / chemistry*, drug effects, metabolism Sulfenic Acids / chemistry, metabolism Sulfhydryl Compounds / chemistry, metabolism Sulfhydryl Reagents / metabolism, pharmacology |
| Grant Support | |
ID/Acronym/Agency:
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1R01AI095173-01/AI/NIAID NIH HHS; R01 AI095173-01/AI/NIAID NIH HHS; //Howard Hughes Medical Institute |
| Chemical | |
Reg. No./Substance:
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0/Fatty Acids; 0/Serum Albumin; 0/Sulfenic Acids; 0/Sulfhydryl Compounds; 0/Sulfhydryl Reagents; 69-78-3/Dithionitrobenzoic Acid; 7722-84-1/Hydrogen Peroxide |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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