Preparative isotachophoresis of human plasma high density lipoproteins HDL2 and HDL3.

HDL2 and HDL3 subclasses of human serum HDL were isolated by preparative ultracentrifugation and further analyzed by isotachophoraesis on polyacrylamide gel. The HDL2 divided into six subfractions and the HDL3 into ten subfractions differing in chemical composition and in apolipoproteinl content. The apoA-I/apoA-II ratios differed widely among the various subfractions. The subfractions with the highest apoA-I/apoA-II ratio appeared to have the greatest affinity for cholesterol. The preparative isotachophoresis, used for the first time in this type of investigation, has high resolving power and is reproducible and thus suitable for use in the study of the structure and metabolism of the lipoproteins.