Studies on pituitary prolactin 39. Reaction of the ovine hormone with hydrogen peroxide Article

Houghten, RA, Li, CH. (1976). Studies on pituitary prolactin 39. Reaction of the ovine hormone with hydrogen peroxide . Biochimica et Biophysica Acta - Protein Structure, 439(1), 240-249. 10.1016/0005-2795(76)90179-3

cited authors

  • Houghten, RA; Li, CH

abstract

  • Three methionine-modified derivatives of ovine prolactin have been prepared: two by oxidation of the methionines by H2O2 to sulfoxide (partial and complete), and the third by complete alkylation of the methionines with iodoacetic acid to the carboxymethyl sulfonium salts. The derivatives were characterized by exclusion chromatography, amino acid composition, circular dichroism spectra, relative rates of digestion by trypsin, and biological activity. Partially oxidized prolactin, having four of its seven methionines oxidized, was very similar to the native hormone. The unmodified methionines in partially oxidized prolactin were found to be the residues at positions 36, 81 and 132. The prolactin derivatives in which all the methionines had been oxidized, or alkylated, showed major changes in all parameters examined. In addition, circular dichroism spectra indicated that complete modification of all the methionines in prolactin exposes the normally buried tryptophans. © 1976.

authors

publication date

  • July 19, 1976

published in

Digital Object Identifier (DOI)

start page

  • 240

end page

  • 249

volume

  • 439

issue

  • 1