Purification and properties of a multifunctional calcium/calmodulin-dependent protein kinase from rat pancreas.
Biochim Biophys Acta
; 928(3): 320-31, 1987 May 18.
Article
em En
| MEDLINE
| ID: mdl-3105599
ABSTRACT
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.
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Bases de dados:
MEDLINE
Assunto principal:
Pâncreas
/
Proteínas Quinases
/
Calmodulina
/
Cálcio
Tipo de estudo:
Prognostic_studies
Limite:
Animals
Idioma:
En
Revista:
Biochim Biophys Acta
Ano de publicação:
1987
Tipo de documento:
Article