title: Antioxidant reactivity toward nitroxide probes anchored into human serum albumin. A new model for studying antioxidant repairing capacity of protein radicals.
abstract: A new strategy to evaluate accessibility of antioxidants to radical proteins has been developed using nitroxide prefluorescent probes anchored into human serum albumin (HSA). Binding association constants for the nitroxide probes C(343)T and QT with HSA were 5 x 10(4) and 9 x 10(4)M(-1), respectively. Rate constants for the nitroxide reduction by antioxidants in HSA were determined finding k(HSA)/k(buffer) ratio of 0.8, 1.9, and 0.075 for ascorbic acid, Trolox, and caffeic acid, respectively, for the nitroxide C(343)T reduction.
authors.affiliation: Facultad de Química y Biología, Universidad de Santiago de Chile, Casilla 40 Correo 33, Santiago, Chile.
authors.forename: Alexis
authors.initials: A
authors.lastname: Aspée
authors.forename: Alejandra
authors.initials: A
authors.lastname: Orrego
authors.forename: Emilio
authors.initials: E
authors.lastname: Alarcón
authors.forename: Camilo
authors.initials: C
authors.lastname: López-Alarcón
authors.forename: Horacio
authors.initials: H
authors.lastname: Poblete
authors.forename: Danilo
authors.initials: D
authors.lastname: González-Nilo
mesh_terms: D000418:Albumins / Q000502:physiology*; D000693:Anaerobiosis / Q000502:physiology; D000975:Antioxidants / Q000378:metabolism*; D001205:Ascorbic Acid / Q000378:metabolism*; D002109:Caffeic Acids / Q000494:pharmacology*; D006801:Humans; D009569:Nitric Oxide / Q000378:metabolism; D012709:Serum Albumin / Q000187:drug effects / Q000378:metabolism*; D013816:Thermodynamics
chemical_list: D000418:Albumins; D000975:Antioxidants; D002109:Caffeic Acids; D012709:Serum Albumin; D009569:Nitric Oxide; D001205:Ascorbic Acid; C040048:caffeic acid