A Balance for Live Animals

Publisher Website
Google Scholar
Abstract
A general review of the chemical study of crystalline insulin is given. The various methods of attacking the problem of the structure of the hormone are outlined. The hormone is of characteristic protein nature. New hydrolytic experiments have confirmed the presence of the following amino acids: cystine, tyrosine, leucine, histidine, arginine and lysine. In addition, glutamic acid has been newly isolated and identified and leucine found in relatively large amounts. Acid-alcohol inactivation of insulin is suggested as due to diketopiperazine formation as well as esterification. Chemical data point to the necessity of both disulfide linkages and free amino groups for physiological activity. Evidence is presented that the ammonia given off on mild alkaline treatment and that given off by acid treatment originate from different parts of the insulin molecule. The results obtained by various chemical treatments may be explained by the assumption of a linkage between cystine and glutamic acid as a part of the active grouping of the insulin molecule.

This publication has 0 references indexed in Scilit: