Properties of the complexes formed by 1-anilinonaphthalene-8-sulfonate with phosphorylase kinase and calmodulin

✍ Scribed by R. F. Steiner; H. Sternberg

• Publisher: Wiley (John Wiley & Sons)
• Year: 1982
• Tongue: English
• Weight: 710 KB
• Volume: 21
• Category: Article
• ISSN: 0006-3525
• DOI: 10.1002/bip.360210710

✦ Synopsis

Abstract

Phosphorylase kinase contains four approximately equivalent binding sites for 1‐anilinonaphthalene‐8‐sulfonate (1,8‐ANS). Measurements of the time decay of fluorescence anisotropy have failed to give any indication of internal degrees of rotational freedom involving a significant portion of the tertiary structure. In the presence of 1 m__M__ Ca^2+^, calmodulin binds one molecule of 1,8‐ANS. No binding occurs in the absence of Ca^2+^. The binding is strongly temperature‐dependent, a decrease in binding occurring with increasing temperature. Determinations of the time decay of fluorescence anisotropy indicate the presence of internal rotations, which become more important with increasing temperature. Complex formation between phosphorylase kinase and calmodulin reduces the binding of 1,8‐ANS.