An apo-E-free very low density lipoprotein enriched in phosphatidylethanolamine in human plasma.

Normal human plasma contains a fraction of very low density lipoprotein (VLDL) which, unlike most VLDL, contains no apolipoprotein E and, unlike apo-E-containing VLDL, is enriched in phosphatidylethanolamine. This fraction made up 0.28 +/- 0.09 of total VLDL triglyceride. Interconversion of the two isolated VLDL fractions was not detected during incubation (2 h, 37 degrees C) and they may represent the physical forms of apo-B corresponding to distinct metabolic pathways in plasma.