title: Liposome-mediated labeling of adrenocorticotropin fragments parallels their biological activity.
abstract: To test our hypothesis that specific interactions of ACTH peptides with model lipid membranes reflect the biological importance of similar interactions on target cells, we investigated the liposome-mediated labeling of ACTH fragments with the extremely hydrophobic photolabel, 3-trifluoromethyl-3-(m-[125I]iodophenyl)diazirine. Correlations were found between the labeling rates and the agonistic and antagonistic potencies of the peptides for in vitro steroidogenesis and inhibition of a synaptosomal protein kinase. A model for the cross-reactivity between ACTH and opioid peptides is discussed.
mesh_terms: D000305:Adrenal Cortex Hormones / Q000096:biosynthesis; D000324:Adrenocorticotropic Hormone / Q000031:analogs & derivatives / Q000378:metabolism* / Q000502:physiology; D001389:Azirines; D055598:Chemical Phenomena; D002621:Chemistry; D008081:Liposomes / Q000378:metabolism*; D010446:Peptide Fragments / Q000378:metabolism* / Q000502:physiology; D011485:Protein Binding; D047428:Protein Kinase Inhibitors; D012995:Solubility; D013574:Synaptosomes / Q000201:enzymology
chemical_list: D000305:Adrenal Cortex Hormones; D001389:Azirines; D008081:Liposomes; D010446:Peptide Fragments; D047428:Protein Kinase Inhibitors; C033174:3-(trifluoromethyl)-3-(3-iodophenyl)diazirine; D000324:Adrenocorticotropic Hormone