Lp(a) and LDL2: differences in fatty acid composition and collagen lattice contraction activity.

Lp(a) and LDL2 were used for detailed fatty acid analyses and tested in an in vitro model for promotion of fibroblast-mediated collagen lattice contraction to determine possible compositional and functional differences between these two apoB-containing lipoprotein species. Autologous Lp(a) was more saturated with respect to fatty acid composition than LDL2 in triglyceride and cholesterol ester lipid classes and had differences in the fatty acid content of phospholipids. Functionally, LDL2 promoted rapid fibroblast-mediated contraction while Lp(a) was significantly less active in promoting rapid contraction on a protein per weight basis. These studies suggest a synthetic route for Lp(a) diverging from the majority of other apoB-containing lipoproteins and significant activity of LDL2 in a collagen lattice contraction system.