Effects of 1-palmitoyl-sn-glycero-3-phosphorylcholine on the properties of a solubilized sialyltransferase activity from mouse liver.
Asialomucin-sialyltransferase (CMP-N-acetylneuraminate:D-galactosyl-glycoprotein N-acetylneuraminyltransferase, EC 2.4.99.1) activity was solubilized from mouse liver microsomes by sonication. The catalytic activity was markedly inhibited by a series of lysophosphatidylcholines, particularly 1-palmitoyl-sn-glycero-3-phosphorylcholine. This lysophospholipid did not alter optimal conditions for enzyme activity. In contrast, it was found that affinities for binding of Mn2+, desialylated mucin and CMP-sialic acid were decreased by adding the lipid. A reasonable interpretation of these data is that the presence of phospholipid modifies the enzyme conformation.
D000818:Animals; D001212:Asialoglycoproteins; D003569:Cytidine Monophosphate N-Acetylneuraminic Acid / Q000378:metabolism; D008244:Lysophosphatidylcholines / Q000494:pharmacology*; D008345:Manganese / Q000378:metabolism; D051379:Mice; D008862:Microsomes, Liver / Q000201:enzymology*; D009077:Mucins / Q000378:metabolism; D012799:Sialyltransferases / Q000037:antagonists & inhibitors* / Q000378:metabolism; D012995:Solubility; D013010:Sonication; D014166:Transferases / Q000037:antagonists & inhibitors*; D000094802:beta-D-Galactoside alpha 2-6-Sialyltransferase
D001212:Asialoglycoproteins; D008244:Lysophosphatidylcholines; D009077:Mucins; C006065:We 201; D003569:Cytidine Monophosphate N-Acetylneuraminic Acid; D008345:Manganese; D014166:Transferases; D012799:Sialyltransferases; D000094802:beta-D-Galactoside alpha 2-6-Sialyltransferase