Self-associated tetramer of human apolipoprotein E does not lead to its accumulation on a lipid particle.

The data of differential measurements of apo E-containing and -free lipid particles in equilibrium binding (J. Biochem. (1989) 105, 582-587) showed complete fit to the calculated curve showing that distribution of apo E among the lipid particles is purely statistical among lipid particles. It was also demonstrated that 5 apo E molecules are required for the saturation of the surface of LDL-size lipid particle in good agreement with 7 +/- 1 given by the binding isotherm. Thus, it is concluded that tetramer formation of apo E in an aqueous phase (J. Biol. Chem. (1985) 260, 16375-16382) does not result in its accumulation on particular lipid particles.