Studies on pituitary adrenocorticotropin. 2. Oxidation–reduction properties of the hormone

Abstract

The conditions for the oxidation of corti-cotropin to a biologically inactive product (assayed by the adrenal ascorbic acid-depletion method) and for the reduction of this material with complete restoration of activity, were investigated. The nature of the groupings concerned in the oxidation-reduction process were examined by studying the effect of various chemical treatments on this process. Amino acid analyses of untreated and oxidized corticotropin A1 are presented. The chemical nature of the oxidation-reduction center is discussed. It is concluded that, with the possible exception of tryptophan, the oxidation-reduction behavior of the hormone cannot be accounted for by the amino acid residues known to be present in the corticotropin molecules.