| Popis: |
Combining HPLC and GLC analyses, 7–13 different molecular species were found in phosphatidylcholine (PC), phosphophatidylethanolamine (PE) and diacylglycerols from pea leaves and germinating soya beans. In soya bean microsomes, the quantitative distributions of molecular species are nearly similar in the three lipid classes, except for the 16:0 18:3 species, which are more abundant in diacylglycerols (20 mol%) than in PC (5.9 mol%) or PE (4.6 mol%). In pea leaf microsomes, the 18:3 18:2 species is predominant (44.5 mol%) in diacylglycerols whereas 16:0 18:2 PC and 16:0 18:2 PE are the major molecular species in phospholipids. Labelling of PC molecular species from CDP[14C]choline reveals that in both pea leaf and soya bean microsomes, cholinephosphotransferase selected actively 1-palmitoyl-2-linoleoyldiacylglycerol as a preferred substrate. The same molecular species was selected by ethanolaminephosphotransferase, as shown by kinetics of labelling from CDP[14C]ethanolamine. However, in both tissues, PE was relatively poorly labelled in its 18:2 18:2 plus 16:0 18:3 fraction as compared with PC. |
