Coenzyme A-independent transacylation in amnion-derived (WISH) cells.
Total membranes or microsomal fractions prepared from the amnion-derived WISH cell line posses a coenzyme A-independent transacylase activity. The transacylase utilizes 1-alkenyl- and 1-alkyl-2-lysoglycerophospholipids as preferred acceptors. Marginal transacylation was observed with 1-acyl-2-lysoglycerophospholipids. The reaction occurred in the presence of ethylene glycol bis(beta-aminoethyl ether)-N,N'-tetraacetic acid and was not affected by phospholipase A2 inhibitors. Both 1-acyl- or 1-alkyl-glycerophosphocholines containing an arachidonoyl residue in the sn-2 position were effective as donors, while 2-oleoyl- or 2-palmitoyl-glycerophosphocholines were ineffective. The presence of the transacylase, the specificity of the substrates, and the stability of the 1-alkenyl bond provide a biochemical model that may explain the increased proportion of a highly enriched arachidonate-containing phosphatidyl-ethanolamine-plasmalogens fraction that is found in amnion at term.
Toyoshima
K
K
Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas 75235-9051.
Narahara
H
H
Frenkel
R A
RA
Johnston
J M
JM
D000215:Acylation; D000217:Acyltransferases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D000650:Amnion / Q000166:cytology*; D016718:Arachidonic Acid / Q000378:metabolism; D002460:Cell Line; D003065:Coenzyme A / Q000494:pharmacology*; D006801:Humans; D008244:Lysophosphatidylcholines / Q000378:metabolism; D010972:Platelet Activating Factor / Q000031:analogs & derivatives / Q000378:metabolism; D013379:Substrate Specificity
C014307:1-acylglycerylphosphorylcholine; D008244:Lysophosphatidylcholines; C029271:O-deacetyl platelet activating factor; D010972:Platelet Activating Factor; D016718:Arachidonic Acid; D000217:Acyltransferases; D003065:Coenzyme A