Accession Number : AD0768642

Title :   The Influence of Gamma-radiation on the Structure and Biological Activity of Oxytocin, a Cyclic Oligopeptide,

Corporate Author : NATIONAL RESEARCH COUNCIL OF CANADA OTTAWA (ONTARIO) DIV OF BIOLOGICAL SCIENCES

Personal Author(s) : Purdie,J. W. ; Lynn,K. R.

Report Date : 17 NOV 1972

Pagination or Media Count : 7

Abstract : During irradiation in aqueous solution under various conditions, the biological activity of oxytocin was lost exponentially, and the following D37 doses were found: aerated, 270 krads; deaerated, 230 krads; N2O saturated, 170 krads; deaerated + butanol, 440 krads. Thus, the hydroxyl radical appeared to be the principal inactivating species. Hydrolysis and analysis of irradiated hormone showed that cystine and tyrosine were the main residues affected. Irradiated oxytocin was resolved into three fractions by gel filtration of Sephadex G-15: The first fraction, which was inactive, predominated in deaerated solution and appeared to consist of dimer or polymer. The third fraction was the major one from aerated and N2O-saturated solutions and had a potency close to that of the original hormone. (Author)

Descriptors :   (*PITUITARY HORMONES, *GAMMA RAYS), (*RADIATION EFFECTS, PITUITARY HORMONES), HORMONES, ATTENUATION, RADIATION DOSAGE, CANADA

Subject Categories : Biochemistry
      Radiobiology

Distribution Statement : APPROVED FOR PUBLIC RELEASE