Radiometric assay of S-adenosylmethionine:calmodulin(lysine)N-methyltransferase by Calcium-dependent hydrophobic interaction chromatography
✍ Scribed by Paul M. Rowe; Timothy J. Murtaugh; Wendy L. Bazari; Margaret Clarke; Frank L. Siegel
- Publisher
- Elsevier Science
- Year
- 1983
- Tongue
- English
- Weight
- 801 KB
- Volume
- 133
- Category
- Article
- ISSN
- 0003-2697
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✦ Synopsis
A radiometric assay for Sadenosylmethionine:calmodulin(lysine)N-methyltransferase in tissue extracts has been developed. This assay utilizes the non-N-methylated calmodulin from Dictyostelium discoideum as a substrate and calciumdependent hydrophobic interaction chromatography to isolate the reaction product, N-methylated calmodulin. The assay measures the transfer of 3H-labeled methyl groups from [methyZ-3H]S-adenosylmethionine to calmodulin. Methylated calmodulin is eluted from phenyl-Sepharose columns with EDTA and protein carboxylmethyl esters are removed by heat treatment prior to liquid scintillation counting of [methy~-3H]calmodulin. This assay is more specific, more sensitive, and more precise than the acid-precipitation assay previously employed and lends itself more readily to the assay of large numbers of samples.