title: Photoreactive derivatives of corticotropin. 1. Preparation and chracterization of 2,4-dinitro-5-azidophenylsulfenyl derivative of corticotropin.
abstract: A photoaffinity probe for corticotropin (ACTH) receptors was prepared by selective modification of the single tryptophan residue in ACTH. A new photoreactive agent, 2,4-dinitro-5-azidophenylsulfenyl chloride, was synthesized and used for introducing the photoreactive group into ACTH. 2,4-Dinitro-5-azidophenylsulfenyl-Trp9-ACTH (DNAPS-ACTH) was also prepared by thiolysis of 2,4-dinitrophenyl-sulfenyl-Trp9-ACTH to form 2-thiol-Trp9-ACTH and reaction of this with 2,4-dinitro-5-azidofluorobenzene. DNAPS-ACTH was characterized by ultraviolet spectra, peptide mapping, and amino acid analysis. Covalent attachment of DNAPS-ACTH to a pituitary protein fraction FI by photolysis was demonstrated by ultraviolet absorption changes as well as by the use of tritiated DNAPS-ACTH.
mesh_terms: D000324:Adrenocorticotropic Hormone / Q000031:analogs & derivatives* / Q000138:chemical synthesis; D000818:Animals; D006801:Humans; D007202:Indicators and Reagents; D008722:Methods; D010446:Peptide Fragments / Q000032:analysis; D010782:Photolysis; D013552:Swine; D014357:Trypsin
chemical_list: D007202:Indicators and Reagents; D010446:Peptide Fragments; C026457:ACTH, 2,4-dinitro-5-azidophenylsulfenyl-; D000324:Adrenocorticotropic Hormone; D014357:Trypsin