Purification and properties of phosphatidyl-N-monomethylethanolamine N-methyltransferase, the enzyme catalyzing the second and the third steps in the phosphatidylethanolamine N-methyltransferase system, from mouse liver microsomes

Jpn J Med Sci Biol. 1990 Jun;43(3):59-73. doi: 10.7883/yoken1952.43.59.

Abstract

The phosphatidylethanolamine (PE) N-methyltransferase (MT) system is known to convert PE to phosphatidylcholine by three successive N-methylations. Phosphatidyl-N-monomethylethanolamine (PME) MT was purified 1,400-fold from mouse liver microsomes and separated from the PE-MT activity for the first time. This enzyme catalyzes N-methylations of PME and phosphatidyl-N,N-dimethylethanolamine, the intermediates of PE-MT system, but not PE, the initial substrate of the PE-MT system. In addition, a preparation with a different affinity to S-adenosyl-L-homocysteine catalyzing all the three methylations was obtained. These results suggest that at least two enzymes are involved in the PE-MT system.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Edetic Acid / pharmacology
  • Hydrogen-Ion Concentration
  • In Vitro Techniques
  • Magnesium Chloride / pharmacology
  • Male
  • Methylation
  • Methyltransferases / isolation & purification*
  • Methyltransferases / metabolism
  • Mice
  • Microsomes, Liver / metabolism
  • Phosphatidyl-N-Methylethanolamine N-Methyltransferase
  • Phosphatidylcholines / metabolism
  • Phosphatidylethanolamine N-Methyltransferase
  • Phosphatidylethanolamines / metabolism
  • Substrate Specificity

Substances

  • Phosphatidylcholines
  • Phosphatidylethanolamines
  • phosphatidyl-N-monomethylaminoethanol
  • Magnesium Chloride
  • Edetic Acid
  • Methyltransferases
  • Phosphatidylethanolamine N-Methyltransferase
  • Phosphatidyl-N-Methylethanolamine N-Methyltransferase