Antioxidant reactivity toward nitroxide probes anchored into human serum albumin. A new model for studying antioxidant repairing capacity of protein radicals

Bioorg Med Chem Lett. 2009 Nov 15;19(22):6382-5. doi: 10.1016/j.bmcl.2009.09.070. Epub 2009 Sep 22.

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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Albumins / physiology*
  • Anaerobiosis / physiology
  • Antioxidants / metabolism*
  • Ascorbic Acid / metabolism*
  • Caffeic Acids / pharmacology*
  • Humans
  • Nitric Oxide / metabolism
  • Serum Albumin / drug effects
  • Serum Albumin / metabolism*
  • Thermodynamics

Substances

  • Albumins
  • Antioxidants
  • Caffeic Acids
  • Serum Albumin
  • Nitric Oxide
  • Ascorbic Acid
  • caffeic acid