title: Interaction of ACTH synthetic fragments with rat adrenal cortex membranes.
abstract: Synthetic peptide, corresponding to the amino acid sequence 11-24 of human adrenocorticotropic hormone (ACTH), was labeled with tritium (specific activity of 22 Ci/mmol). [(3)H]ACTH (11-24) was found to bind to rat adrenal cortex membranes with high affinity and specificity (K(d) = 1.8 +/- 0.1 nM). Twenty nine fragments of ACTH (11-24) have been synthesized and their ability to inhibit the specific binding of [(3)H]ACTH (11-24) to adrenocortical membranes has been investigated. Unlabeled fragment ACTH 15-18 (KKRR) was found to replace in a concentration-dependent manner [(3)H]ACTH (11-24) in the receptor-ligand complex (K(i) = 2.3 +/- 0.2 nM). ACTH (15-18) was labeled with tritium (specific activity of 20 Ci/mmol). [(3)H]ACTH (15-18) was found to bind to rat adrenal cortex membranes with high affinity (K(d) = 2.1 +/- 0.1 nM). The specific binding of [(3)H]ACTH (15-18) was inhibited by unlabeled ACTH (11-24) (K(i) = 2.2 +/- 0.1 nM). ACTH (15-18) at the concentration range of 1-1000 nM did not affect the adenylate cyclase activity in adrenocortical membranes.
authors.affiliation: Branch of Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry of Russian Academy of Science, Science Avenue 6, Pushchino, Moscow Region 142290, Russia.
authors.forename: Yulia A
authors.initials: YA
authors.lastname: Kovalitskaya
authors.forename: Yury A
authors.initials: YA
authors.lastname: Zolotarev
authors.forename: Alexander A
authors.initials: AA
authors.lastname: Kolobov
authors.forename: Vladimir B
authors.initials: VB
authors.lastname: Sadovnikov
authors.forename: Vladimir V
authors.initials: VV
authors.lastname: Yurovsky
authors.forename: Elena V
authors.initials: EV
authors.lastname: Navolotskaya
mesh_terms: D000262:Adenylyl Cyclases / Q000378:metabolism; D000302:Adrenal Cortex / Q000378:metabolism*; D000324:Adrenocorticotropic Hormone / Q000138:chemical synthesis / Q000378:metabolism* / Q000494:pharmacology; D000818:Animals; D002462:Cell Membrane / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D004789:Enzyme Activation / Q000187:drug effects; D006801:Humans; D010455:Peptides / Q000138:chemical synthesis / Q000378:metabolism* / Q000494:pharmacology; D011485:Protein Binding / Q000502:physiology; D051381:Rats; D018043:Receptors, Corticotropin / Q000378:metabolism*; D014316:Tritium / Q000737:chemistry
chemical_list: D010455:Peptides; D018043:Receptors, Corticotropin; D014316:Tritium; D000324:Adrenocorticotropic Hormone; D000262:Adenylyl Cyclases