A study of adenosine 3′-5′ cyclic monophosphate binding sites of human erythrocyte membranes using 8-azidoadenosine 3′-5′ cyclic monophosphate, a photoaffinity probe

✍ Scribed by Owens, James R. ;Haley, Boyd E.

• Book ID: 102925495
• Publisher: Wiley (John Wiley & Sons)
• Year: 1976
• Tongue: English
• Weight: 755 KB
• Volume: 5
• Category: Article
• ISSN: 0091-7419
• DOI: 10.1002/jss.400050110

✦ Synopsis

An earlier report (la) has shown the utility of 8-N3 cAMP (8-azidoadenosine-3', 5'-cyclic monophosphate) as a photoaffinity probe for cAMP binding sites in human erythrocyte membranes. The increased resolution obtained using a linear-gradient SDS polyacrylamide gel system now shows that: 1) both cAMP and 8-N3 cAMP stimulate the phosphorylation by [y-32P]-ATP of the same red cell membrane proteins; 2) the protein of approximately 48,000 molecular weight whose phosphorylation by [y-32P] -ATP is stimulated by cAMP and 8-N3cAMP migrates at a slower rate than the protein in the same molecular weight range which is heavily photolabeled with [32P] -8-N3 CAMP; 3) other cyclic nucleotide binding sites exist besides those initially reported; 4) the variation in the ratio of incorporation of [ 3 2 PI -8-N3cAMP into the two highest affinity binding sites appears to be the result of a specific proteolysis of the larger protein.