Conversion of the Cleavage Specificity of Subtilisin YaB on Oxidized Insulin Chains to an Elastase-like Specificity by Replacement of Gly124 with Ala

Abstract

  Replacement of Gly124 on the S1 pocket of subtilisin YaB with Ala changed the cleavage pattern on oxidized insulin B-chain from the subtilisin type to the elastase type. The initial cleavage site in the B-chain shifted from L15-Y16 for wild-type YaB to A14-L15 for the G124A mutant. Upon complete hydrolysis with the G124A mutant, four of the six major cleavage sites on the B-chain were identical to porcine pancreatic elastase cleavage sites.