Reaction of insulin with reduced glutathione

An aggregate of insulin, molecular weight about 70,000, was formed when it was incubated with GSH. The aggregate product converted to a low molecular weight product, presumably the insulin A- and B-chains, on addition of urea to mixtures. This conversion requires sulfhydryl-disulfide interchange as a sulfhydryl reagent inhibited it, in part. The aggregate does not form with EDTA in mixtures, but as before, a product of lower molecular weight than insulin was formed. These results support the previously held view that the disulfide bonds formed by insulin are influenced by its structure.