Purification and properties of calmodulin-lysine N-methyltransferase from rat brain cytosol

J Neurochem. 1987 Apr;48(4):1201-8. doi: 10.1111/j.1471-4159.1987.tb05647.x.


A S-adenosylmethionine:protein-lysine N-methyltransferase (EC has been purified from rat brain cytosol 7,080-fold with a yield of 8%, using octopus calmodulin as a substrate. It contains a lysine residue that is not fully methylated. The enzyme was purified by ammonium sulfate fractionation, Sephacryl S-200 gel filtration, and phosphocellulose and octopus calmodulin-Sepharose affinity chromatographies. Among protein substrates, it was highly specific toward octupus calmodulin. The Km values for octopus calmodulin and S-adenosyl-L-methionine were found to be 2.2 X 10(-8) M and 0.8 X 10(-6) M, respectively. The molecular weight was estimated to be 57,000 by gel filtration and the pH optimum was between 7.5 and 8.5. The enzyme was stimulated in the presence of 10(-7) M Mn2+ and 10(-4) M Ca2+. HPLC of the acid hydrolysate of methyl-3H-labeled calmodulin showed the formation of epsilon-N-mono, epsilon-N-di, and epsilon-N-trimethyllysine. Reverse-phase HPLC of tryptic peptides of the methyl-3H-labeled calmodulin demonstrated that the labeled N-methyllysine lies in the 107-126 peptide. These findings suggest that this enzyme methylated a specific lysine residue of octopus calmodulin.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Brain / enzymology*
  • Calmodulin / metabolism
  • Chemical Precipitation
  • Chromatography
  • Chromatography, High Pressure Liquid
  • Cytosol / enzymology
  • Electrophoresis, Polyacrylamide Gel
  • Lysine / metabolism
  • Methylation
  • Methyltransferases / isolation & purification*
  • Methyltransferases / metabolism
  • Molecular Weight
  • Octopodiformes
  • Rats
  • Rats, Inbred Strains
  • Substrate Specificity


  • Calmodulin
  • Methyltransferases
  • calmodulin-lysine methyltransferase
  • Lysine