A simplified approach to the analysis of subclasses of phospholipids: application to human platelets.
A procedure for the determination of the proportions of diacyl, alkenylacyl and alkylacyl subclasses of glycerophospholipids was developed. The procedure involves: (1) acid methanolysis of the phospholipid followed by Bligh/Dyer extraction of fatty acid methyl esters (FAME) derived from acyl chain types, dimethylacetals (DMA) derived from alkenyl ether chain types, and lysoalkyl phosphatidic acids (lysoalkyl-PA) derived from alkyl ether chain types; and (2) subsequent acetolysis to convert the lysoalkyl-PA to monoalkyl glycerol diacetates (MAGD). GLC analysis and quantitation (using internal standard, 21:0 FAME) of FAME, DMA and MAGD allowed calculation of the proportions of the three molecular subclasses. The methanolysis/acetolysis procedure gave an overall mean phospholipid recovery of 95 +/- 3%. Analysis of the major phospholipids in four separate preparations of fresh resting human platelets by this procedure showed the following range of molecular subclasses: phosphatidylcholine (PC), 86-92 mol % diacyl, 6-10 mol % alkylacyl and 2-3 mol % alkenylacyl; and phosphatidylethanoline (PE), 39-60 mol % diacyl, 5-8 mol % alkylacyl and 34-55 mol % alkenylacyl. The results of these subclass analyses were in general agreement with those reported in the literature.
Vishnubhatla
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I
Department of Biochemistry, University of Ottawa, Canada.
Kates
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M
Adams
G A
GA
D000085:Acetates; D019342:Acetic Acid; D000089:Acetic Anhydrides; D001792:Blood Platelets / Q000032:analysis*; D002849:Chromatography, Gas; D006801:Humans; D006868:Hydrolysis; D000432:Methanol; D008722:Methods; D010743:Phospholipids / Q000097:blood* / Q000145:classification
D000085:Acetates; D000089:Acetic Anhydrides; D010743:Phospholipids; C031800:acetic anhydride; D019342:Acetic Acid; D000432:Methanol