Acylation of endogenous acyl acceptors by mouse sciatic nerve microsomes.
Phospholipid (chiefly phosphatidylcholine) labeling from radioactive acyl-CoAs by mouse sciatic nerve microsomes is observed in the absence of added acyl acceptors. The maximal acylation (ca 10% of administered) for 10 micrograms microsomal proteins is observed at relatively low amounts of oleoyl-CoA (0.2-0.3 nmol) and decreases as the acyl-CoA amount increases. Labeled lysophosphatidylcholine (almost exclusively esterified at position 2) is also observed, particularly when the [1-14C]oleoyl-CoA concentration is higher than 0.2-0.3 nmol/50 microliters. The labeled acyl group is mainly inserted in position 2] of the glycerophosphorylcholine. With 0.15 nmol labeled oleoyl-CoA, phosphatidylcholine acylation increases as a function of the protein amount and reaches 25% of the added label at 40 microgram proteins. It is evaluated that, in the presence of 10 microgram proteins, 2% of the microsomal phosphatidylcholine molecules are acylated from 0.1 nmol acyl-CoA. The acylation mechanism seems to involve an acyl exchange between acyl-CoA and phosphatidylcholine.
Juguelin
H
H
Laboratoire de Biogenése Membranaire, Université de Bordeaux 2-URA-CNRS 1811, France.
Bessoule
J J
JJ
Boiron
F
F
Heape
A
A
Garbay
B
B
Testet
E
E
Cassagne
C
C
D000214:Acyl Coenzyme A / Q000378:metabolism*; D000215:Acylation; D000818:Animals; D007700:Kinetics; D050356:Lipid Metabolism; D051379:Mice; D008808:Mice, Inbred CBA; D008861:Microsomes / Q000378:metabolism*; D010741:Phospholipases A / Q000378:metabolism; D010743:Phospholipids / Q000378:metabolism; D012584:Sciatic Nerve / Q000378:metabolism*
D000214:Acyl Coenzyme A; D010743:Phospholipids; C017585:oleoyl-coenzyme A; D010741:Phospholipases A