Interaction of ACTH synthetic fragments with rat adrenal cortex membranes

✍ Scribed by Yulia A. Kovalitskaya; Yury A. Zolotarev; Alexander A. Kolobov; Vladimir B. Sadovnikov; Vladimir V. Yurovsky; Elena V. Navolotskaya

• Book ID: 105360694
• Publisher: John Wiley and Sons
• Year: 2007
• Tongue: English
• Weight: 138 KB
• Volume: 13
• Category: Article
• ISSN: 1075-2617
• DOI: 10.1002/psc.873

✦ Synopsis

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. Copyright © 2007 European Peptide Society and John Wiley & Sons, Ltd.