Studies on the Redox State in Polyacrylamide Gels

Abstract

Abstract The oxidation-reduction properties of polyacrylamide gels were examined to test the possibility that persulfate-or other free radical donors-alter proteins during polyacrylamide gel electrophoresis. Polyacrylamide gels formed either by use of persulfate or riboflavin and light as catalysts were shown to oxidize sulfhydryl compounds. Electrophoresis of thioglycolate into the gel in amounts equivalent to persulfate resulted in reducing conditions (titratable SH groups) in the gel. Acrylamide monomer and, therefore, presumably unreacted monomer in polyacrylamide react with the α-amino group of amino acids: the reaction with glycine proceeded slowly at pH 9 and at acrylamide concentrations comparable to that of amino acid. Acrylamide at high concentrations (0.5 M) also reacted with yeast enolase and, like the thiol groups of reduring agents, prevented the appearance of characteristic changes in the pattern of enolase in polyacrylamide gel electrophoresis, previously attributed to “persulfate damage” ...