title: Structural Response of Human Serum Albumin to Oxidation: Biological Buffer to Local Formation of Hypochlorite.
abstract: The most abundant plasma protein, human serum albumin (HSA), plays a key part in the body's antioxidant defense against reactive species. This study was aimed at correlating oxidant-induced chemical and structural effects on HSA. Despite the chemical modification induced by the oxidant hypochlorite, the native shape is preserved up to oxidant/HSA molar ratio <80, above which a structural transition occurs in the critical range 80-120. This conformational variation involves the drifting of one of the end-domains from the rest of the protein and corresponds to the loss of one-third of the α-helix and a net increase of the protein negative charge. The transition is highly reproducible suggesting that it represents a well-defined structural response typical of this multidomain protein. The ability to tolerate high levels of chemical modification in a folded or only partially unfolded state, as well as the stability to aggregation, provides albumin with optimal features as a biological buffer for the local formation of oxidants.
authors.affiliation: Department of Chemistry, Sapienza University of Rome , P. le A. Moro 5, 00185 Rome, Italy.
authors.forename: Alessandra
authors.initials: A
authors.lastname: Del Giudice
authors.affiliation: Department of Chemistry, Division for Pure and Applied Biochemistry, Lund University , Naturvetarvägen 14, 2241 Lund, Sweden.
authors.forename: Cedric
authors.initials: C
authors.lastname: Dicko
authors.affiliation: Department of Chemistry, Sapienza University of Rome , P. le A. Moro 5, 00185 Rome, Italy.
authors.forename: Luciano
authors.initials: L
authors.lastname: Galantini
authors.affiliation: Department of Chemistry, Sapienza University of Rome , P. le A. Moro 5, 00185 Rome, Italy.
authors.forename: Nicolae V
authors.initials: NV
authors.lastname: Pavel
mesh_terms: D006801:Humans; D006997:Hypochlorous Acid / Q000138:chemical synthesis* / Q000737:chemistry / Q000378:metabolism; D010084:Oxidation-Reduction; D011487:Protein Conformation; D012709:Serum Albumin / Q000737:chemistry* / Q000378:metabolism
chemical_list: D012709:Serum Albumin; D006997:Hypochlorous Acid