Quantitation and significance of 125I-calmodulin binding to myosin light chain kinase and phosphorylase distributed on polyacrylamide gels.

Journal Article (Journal Article)

Glycogen phosphorylase (a or b) binds 125I-calmodulin in a Ca2+-dependent manner, in the 125I-calmodulin overlay technique. This binding is quantitatively identical to 125I-calmodulin binding to myosin light chain kinase. In an in vitro assay, calmodulin stimulates phosphorylase activity at limiting concentrations of either glucose-1-phosphate or glycogen, but the Ka is 1000 fold higher than for the kinase, and is not Ca2+-dependent. Activation of phosphorylase, but not myosin light chain kinase, by calmodulin can be mimicked by troponin C or bovine serum albumin. These results demonstrate that the properties of calmodulin interaction with proteins can vary between the 125I-calmodulin technique and a functional assay of calmodulin effect on the same protein.

Full Text

Duke Authors

Cited Authors

  • Slaughter, GR; Means, AR

Published Date

  • January 16, 1985

Published In

Volume / Issue

  • 126 / 1

Start / End Page

  • 295 - 303

PubMed ID

  • 3918530

International Standard Serial Number (ISSN)

  • 0006-291X

Digital Object Identifier (DOI)

  • 10.1016/0006-291x(85)90605-9


  • eng

Conference Location

  • United States