[Two-dimensional immunoelectrophoresis of spontaneous dissociation of low density lipoproteins].

Plasma-lipoproteins isolated between d 1.020 and d 1.055 g/ml were partially delipidated with ethyl ether at 4 degrees C. This treatment induces a transformation of the lipoproteins which is evolutive during several days. Bidimensional immunoelectrophoresis reveals the lipoproteins dissociation and the appearance of 4 immunologically different fractions. The time dependent formation of these subunits is slowed down by EDTA and less efficiently by antioxydants. Once started, the dissociation can be accelerated by heating at 37 degrees C or by UV exposition. Another lipopeptide is more easily revealed by anti VLDL antiserum. It can be shown in the native and in the partially or completely delipidated LDL. Its presence does not depend on lipoprotein dissociation.