Differential effects of cysteine and methionine residues in the antioxidant activity of human serum albumin
| Autor: | Nadine Loreau, Laurent Lagrost, Denis Blache, Emmanuel Bourdon |
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| Rok vydání: | 2005 |
| Předmět: |
Time Factors
Antioxidant Free Radicals medicine.medical_treatment Dithionitrobenzoic Acid Hemolysis Biochemistry Antioxidants Tosyl Compounds chemistry.chemical_compound Methionine medicine Humans Chelation Cysteine Serum Albumin Dose-Response Relationship Drug Chloramines Free Radical Scavengers General Medicine Free radical scavenger Human serum albumin medicine.disease Lipoproteins LDL Oxygen Oxidative Stress chemistry Ethylmaleimide Chloramine-T Oxidation-Reduction Copper Phenanthrolines Protein Binding medicine.drug |
| Zdroj: | Free Radical Research. 39:15-20 |
| ISSN: | 1029-2470 1071-5762 |
| Popis: | Antioxidant properties of human serum albumin (HSA) may explain part of its beneficial role in various diseases related to free radical attack. In the present study, the antioxidant role of Cys and Met was studied by copper-mediated oxidation of human low density lipoproteins and by free radical-induced blood hemolysis which essentially assessed metal-chelating and free radical scavenging activities, respectively. Mild conditions were set up to specifically modify Cys and Met residues by N-ethylmaleimide (NEM) and chloramine T treatments, respectively. We found that Met and Cys accounted for 40-80% of total antioxidant activity of HSA. Copper binding to HSA was decreased by about 50% with chloramine T treatment of Met whereas no change was observed after NEM treatment of Cys. Although other amino acid residues are likely to be involved in anti-/prooxidant properties of HSA, from our data, we propose that Cys chiefly works as a free radical scavenger whereas Met mainly acts as a metal chelator. |
| Databáze: | OpenAIRE |
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