Acylation of Lysophospholipids Including Lysoplasmalogen by Cultured Human Amnion Cells (FL Cells)

Abstract

1. Enzymatic acylation of lysophospholipids was studied in a cultured cell line, FL cells, derived from human amniotic membrane. Acylation with radioactive oleic acid of lysophosphatidylcholine, which was prepared from egg yolk phosphatidylcholine by means of snake venom, in the presence of ATP, CoA, and Mg²⁺ occurred more actively with FL cell homogenate than with bovine erythrocyte hemolysate. Lysophosphatidylethanolamine was acylated at a slightly lower rate than lysophosphatidylcholine by FL cells.
2. Lysoplasmalogens (1-alkenyl-glycerophosphorylcholine and 1-alkenyl-glycerophosphorylethanolamine) were also quite highly acylated by FL cells. The rate of acylation of the former was higher than that of the latter.
3. In addition, the venom of a Japanese snake, Trimeresurus flavoviridis, was found to contain phospholipase A₂ activity which specifically attacks the 2-position of glycerophospholipid; phospholipase A₁ activity, which hydrolyzes the 1-position of the substrate, was practically negligible.