PMID: 8443229Feb 24, 1993Paper

Phospholipid methylation in brain membrane preparations: kinetic mechanism

Biochimica Et Biophysica Acta
R C ReitzW H Welch

Abstract

The methylation reactions which convert phosphatidylethanolamine (PE) to phosphatidylcholine (PC) have been studied kinetically using exogenously added intermediates and crude membrane preparations from brain. The addition of exogenous PE resulted in no change in the methylation rates compared to that of endogenous PE. The addition of the two intermediates, monomethylphosphatidylethanolamine (PMME) and dimethylphosphatidylethanolamine (PDME), resulted in significantly increased rates of methylation and allowed the kinetic analysis of these latter two methylation reactions. The mechanism for this enzyme appears to be similar to human RBC (Reitz et al. (1989) J. Biol. Chem. 264, 8097-8106) which was a rapid-equilibrium random Bi-Bi sequential mechanism. There were some slight differences between the brain enzyme and that from the RBC, but there is little reason to suggest a fundamentally different mechanism. It is more likely that the differences may relate to an additional dead-end complex for the enzyme from brain such that saturation with AdoMet cannot eliminate AdoHcy inhibition. The KM values for the two phospholipid substrates were 41-44 microM and 39 microM for the methylation of PMME and PDME, respectively. The KM for S-a...Continue Reading

References

Apr 16, 1985·Biochemical and Biophysical Research Communications·V S Bansal, J N Kanfer
Sep 1, 1985·Journal of Neurochemistry·M Tacconi, R J Wurtman
May 1, 1966·Analytical Biochemistry·S K Shapiro, D J Ehninger
Aug 1, 1959·Canadian Journal of Biochemistry and Physiology·E G BLIGH, W J DYER
Aug 1, 1961·The Biochemical Journal·G N WILKINSON

❮ Previous
Next ❯

Related Concepts

Related Feeds

Basal Ganglia

Basal Ganglia are a group of subcortical nuclei in the brain associated with control of voluntary motor movements, procedural and habit learning, emotion, and cognition. Here is the latest research.