Sulfhydryl Factors in Degradation of lnsulin-l 131 by Liver Extracts. ∗

Abstract

Summary

1. Glutathione degrades in-sulin-l¹³¹ and renders it more soluble in tri-chloroacetic acid. Evidence is presented that this is not the result of direct deiodination. 2. Rat liver extracts, even after exposure to a boiling water bath, can degrade insulin-l¹³¹. This heat stable activity could be explained by the presence of sulfhydryl compounds in liver. 3. Reductive as well as proteolytic processes must be considered when analyzing the degradation of insulin by crude liver extracts.

The authors are indebted to Miss Ruth Miller for valuable technical assistance.