Intercellular glycoproteins and low density lipoprotein binding to fibroblasts.

The interaction of low density lipoprotein (LDL) with solubilized subunits of two purified noncollagenous glycoproteins (A and G) of cartilage matrix have been studied in solution using Sepharose chromatography and at the cell surface using fibroblast monolayers. In the presence of A or G, [125I]-LDL forms aggregates of varying size. After pre-incubation with A or G, under conditions which form highly aggregrated complexes, there is an increase in the binding of LDL to fibroblasts. Mixing with A under conditions which form smaller complexes produced no increase in binding to fibroblasts. It is suggested that interactions of this type may be involved in the pathogenesis of atherosclerosis.