Year: 1955
Type: article
Abstract: In order to deduce the unique structure of ox insulin it is necessary to know its molecular weight.In previous papers a value of 12 000 was assumedc since physical measurements suggested that this was the weight of the smallest unit that existed in solution, Recently, however, Harfenist & Craig (1952) have used a new chemical method and have found a value of approximately 6000.It is difficult to see how this result could be wrong and some recent physical measurements have shown that dissociation into units of molecular weight lower than 12 000 definitely occurs (Fredericq, 1953; Kupke & Linderstrom-Lang, 1954).It may thus safely be concluded that the molecular weight of insulin is 5734, on the basis of condensation of the amino acids present with normal elimination of water.This molecule is composed of two poly- peptide chains joined together by the disulphide bridges of three cystine residues.Treatment with performic acid splits the insulin to two fractions A and B, which are the oxidized forms of the glycyl and the phenylalanyl chain respectively (Sanger, Table 3. Jy8teic acid peptides obtained from crude 'tryptic' hydroly8ate of insuin (Expt.Ix)
Source: Biochemical Journal
DOI: 10.1042/bj0600541
Authors: A. P. Ryle, F. Sanger, L. F. Smith, Ruth Kitai
Institution: University of Cambridge
Language: English
Subfield: Endocrinology, Diabetes and Metabolism
Field: Medicine
Domain: Health Sciences
Open Access status: bronze
OpenAlex ID: W2414829511