Über die partielle Reduktion von Insulin

Publisher Website
Google Scholar
Abstract
Insulin was partially cleaved by mercaptoethanol by controlling the pH and the concentration of the reductant mercaptan. The resulting thiol groups were carboxymethylated. The carboxymethylated reaction products were separated by gel filtration and ion exchange chromatography and characterized by electrophoresis and polarographic disulfide analysis. The A-chain with an intact 6.11-disulfide ring was separated from the reaction products. Electroreduction at a controlled potential showed that the A 6[long dash]11-disulfide bridge is cleaved more slowly than the interchain disulfide bonds in acid solution. In acid solution, the A7-B7-disulfide bond is preferentially cleaved by mercaptoethanol. Above pH3, all partial mercaptolyses by thiol-disulfide exchange are accompanied by a secondary reaction, which produces polymers with a high content of B-chain. Polymer formation is inhibited if the insulin is bound to DEAE-cellulose during the reduction. Insulin is cleaved by reduced B-chain, but the intra-A-chain disulfide ring is not attacked.

This publication has 2 references indexed in Scilit: