Plasma HDL can be classified according to their apolipoprotein content into at least two types of lipoprotein particles: lipoproteins containing both apo A-I and apo A-II (LP A-I/A-II) and lipoproteins with apo A-I but without apo A-II (LP A-I). LP A-I and LP A-I/A-II were isolated by immuno-affinity chromatography. LP A-I has a higher cholesterol content and less protein compared to LP A-I/A-II. The average particle mass of LP A-I is higher (379 kDa) than the average particle weight of LP A-I/A-II (269 kDa). The binding of 125I-LP A-I to HepG2 cells at 4°C, as well as the uptake of [3H]cholesteryl ether-labelled LP A-I by HepG2 cells at 37° C, was significantly higher than the binding and uptake of LP A-I/A-II. It is likely that both binding and uptake are mediated by apo A-I. Our results do not provide evidence in favor of a specific role for apo A-II in the binding and uptake of HDL by HepG2 cells.

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doi.org/10.1016/0005-2760(90)90121-D, hdl.handle.net/1765/71441
Biochimica et Biophysica Acta - Lipids and Lipid Metabolism
Department of Biochemistry

Kilsdonk, L., van Gent, T., & van Tol, A. (1990). Characterization of human high-density lipoprotein subclasses LP A-I and LP A-I/A-II and binding to HepG2 cells. Biochimica et Biophysica Acta - Lipids and Lipid Metabolism, 1045(3), 205–212. doi:10.1016/0005-2760(90)90121-D