Purification and properties of a multifunctional calcium/calmodulin-dependent protein kinase from rat pancreas.

Journal Article

A calcium/calmodulin-dependent protein kinase (Ca/calmodulin protein kinase) was purified from rat pancreas using hydrophobic chromatography followed by gel filtration and affinity chromatography. Ca/calmodulin protein kinase from pancreas resembled previously described multifunctional Ca/calmodulin protein kinases from other tissues with respect to substrate specificity, autophosphorylation on serine and threonine residues, and catalytic and hydrodynamic properties. While Ca/calmodulin protein kinase from other tissues contains subunits of 53-60 kDa with variable proportions of a smaller 50-52 kDa subunit, pancreatic Ca/calmodulin protein kinase was found to contain a single component of 51 kDa. Experiments mixing brain Ca/calmodulin protein kinase with pancreatic homogenate suggest that the absence of a larger subunit in the pancreatic Ca/calmodulin protein kinase is not due to proteolytic degradation during enzyme preparation. Ca/calmodulin protein kinase binding to 125I-labeled calmodulin in solution was demonstrated using the photoaffinity cross-linker, N-hydroxysuccinimidyl-4-azidobenzoate. 125I-labeled calmodulin binding to Ca/calmodulin protein kinase was also demonstrated using filters containing Ca/calmodulin protein kinase transferred from polyacrylamide gels after two-dimensional gel electrophoresis. Finally, the ribosomal substrate for Ca/calmodulin protein kinase was identified as the ribosomal protein, S6. The purification procedure presented in this study promises to be useful in characterizing Ca/calmodulin protein kinase in other tissues and in clarifying the role of these enzymes in cellular function.

Full Text

Duke Authors

Cited Authors

  • Cohn, JA; Kinder, B; Jamieson, JD; Delahunt, NG; Gorelick, FS

Published Date

  • May 18, 1987

Published In

Volume / Issue

  • 928 / 3

Start / End Page

  • 320 - 331

PubMed ID

  • 3105599

International Standard Serial Number (ISSN)

  • 0006-3002

Language

  • eng

Conference Location

  • Netherlands