Lysophosphatidylserine dependent incorporation of acyl CoA into phospholipids in rat brain microsomes.
[(14)C]OleoylCoA was incorporated into phosphatidylinositol 41 2 times more efficiently than into phosphatidylserine in rat brain and liver microsomes when incubated with various levels of 1-acyl-sn-glycero-3-phosphoserine. In contrast, 1-acyl-sn-glycero-3-phosphocholine dependent incorporation of oleoylCoA was only into phosphatidylcholine. When [l-(3)H]serine labeled 1-acyl-sn-glycero-3-phosphoserine was used as the labeled substrate, no phosphatidylserine synthesis could be detected in rat brain microsomes. OleoylCoA incorporation in phospholipids in the presence of lysophosphatidylserine was primarily at the 2-position while stearoylCoA was incorporated at the 1-position. These results are interpreted to suggest that there is no acylCoA:1-acyl-sn-glycero-3-phosphoserine acyltransferase in rat brain microsomes and the lysophosphatidylserine dependent position-specific incorporation of acylCoA into various phospholipids may be due to an exchange reaction. A simple highly reproducible one dimensional thin-layer chromatographic system is described for the separation of all the major phospholipids of brain and liver.
Sbaschnig-Agler
M
M
Department of Neurochemistry, New York State Institute for Basic Research in Developmental Disabilities, 1050 Forest Hill Road, Staten Island, NY 10314, U.S.A.
Pullarkat
R K
RK