The Use of Ascorbic Acid to Promote the Polymerization of 11S Globulin

Abstract

We investigated the effects of L-ascorbic acid (AsA) on 11S globulin, which was reduced by 2-mercaptoethanol. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis verified that AsA promoted the polymerization of 11S globulin via the formation of disulfide bridges. The generation of thiyl radicals (S·) in 11S globulin was examined by electron spin resonance spectroscopy coupled with spin trapping. The superoxide anion radical (O^-₂ ) was produced by the photoactivation of riboflavin. A typical line shape was observed for S·. Staining with nitroblue tetrazolium dye confirmed that O^-₂ was produced in the 11S globulin solution due to the autooxidation of AsA. Although the 11S globulin lacking AsA did not yield a rigid gel, the sample containing AsA successfully yielded a rigid gel. Thus, it is clear that O^-₂ generated during AsA oxidation exerts beneficial effects on 11S globulin in its reduced form.