1-O-alkyl-linked glycerophospholipids of human neutrophils: distribution of arachidonate and other acyl residues in the ether-linked and diacyl species.
This study was done to determine whether human neutrophils contain sufficient 1-O-alkyl-2-acyl-sn-glycero-3-phosphocholine to support the synthesis of platelet activating factor by a deacylation-reacylation mechanism, and to examine the relative distribution of arachidonate among the 1,2-diacyl, 1-O-alkyl-2-acyl, and the 1-O-alk-1'-enyl-2-acyl classes of choline- and ethanolamine-containing phospholipids. The predominant phospholipid species of human neutrophils were choline-containing glycerophospholipids (41%), ethanolamine-containing glycerophospholipids (39%), and sphingomyelin (14%), with smaller quantities of phosphatidylserine (4%) and phosphatidylinositol (1%). The choline-linked fraction contained high amounts of 1-O-alkyl-2-acyl-X (44%) and 1,2-diacyl-sn-glycero-3-phosphocholine (47%), and a lesser amount of 1-O-alk-1'-enyl-2-acyl-sn-glycero-3-phosphocholine (9%). In contrast, the ethanolamine-linked fraction contained a large amount of 1-O-alk-1'-enyl-2-acyl-sn-glycero-3-phosphoethanolamine (66%), and lower levels of the 1,2-diacyl (24%) and 1-O-alkyl-2-acyl (10%) species. The major 1-O-alkyl and 1-O-alk-1'-enyl ether chains found in the choline and ethanolamine phospholipid pools were 16:0, 18:0, 18:1, and 20:0. The predominant fatty acyl residues found in the 1,2-diacyl and the sn-2 position of the 1-O-alkyl-2-acyl and 1-O-alk-1'-enyl-2-acyl choline and ethanolamine glycerophospholipids were 16:0, 18:0, 18:1, 18:2, and 20:4.(ABSTRACT TRUNCATED AT 250 WORDS)
D000215:Acylation; D016718:Arachidonic Acid; D001095:Arachidonic Acids / Q000097:blood*; D004987:Ethers; D005227:Fatty Acids / Q000097:blood; D008401:Gas Chromatography-Mass Spectrometry; D005997:Glycerylphosphorylcholine / Q000097:blood*; D006801:Humans; D009504:Neutrophils / Q000378:metabolism*; D010714:Phosphatidylethanolamines / Q000097:blood*; D010716:Phosphatidylinositols / Q000097:blood; D010718:Phosphatidylserines / Q000097:blood; D010972:Platelet Activating Factor / Q000031:analogs & derivatives* / Q000096:biosynthesis / Q000502:physiology; D013109:Sphingomyelins / Q000097:blood
C036761:1-alkyl-2-acyl-sn-glycero-3-phosphocholine; D001095:Arachidonic Acids; D004987:Ethers; D005227:Fatty Acids; D010714:Phosphatidylethanolamines; D010716:Phosphatidylinositols; D010718:Phosphatidylserines; D010972:Platelet Activating Factor; D013109:Sphingomyelins; C002449:glycerophosphoethanolamine; D016718:Arachidonic Acid; D005997:Glycerylphosphorylcholine