Immunoelectronmicroscopy of the binding of high density lipoprotein apoproteins to normal and hypercholesterolemic human fibroblasts

We visualized the apolipoproteins of high density lipoproteins (HDL) that were bound to cultured human fibroblasts at the ultrastructural level, with an immunoenzymecytochemical method. By using antisera against (a) apolipoprotein AI (a major apolipoprotein of HDL) and (b) apolipoprotein E (an apolipoprotein present in HDL), the binding of HDL at 4??C to indentations of the plasma membrane could be demonstrated. The binding of HDL to fibroblasts obtained from a patient homozygous for familial hypercholesterolemia proved to be indistinguishable from the binding to normal fibroblasts. Chemicals/CAS: Apolipoprotein A-I; apolipoprotein E-A-II; Apolipoproteins; Lipoproteins, HD