[Effects of apolipoproteins AI, CI, CII, CIII and E on the binding of 125I-labeled apoE-deficient HDL3 to rat liver plasma membranes].

Effects of purified human apolipoproteins AI, CI, CII, CIII-1, Cs and E on the binding of 125I-labeled apo E-deficient HDL3 to isolated rat liver plasma membranes were investigated. Unlabeled apo AI, CI, CII, CIII-1 and apo Cs, but not apo E, could effectively inhibit 125I-labeled HDL3 binding to liver membranes, apoCIII-1, was the strongest among the apoC subclasses and the inhibition curve of apoCIII-1 was similar to that of apo AI. This result indicates that apo C, especially apo CIII, may be another specific ligand of HDL receptor, and it plays an important role in regulation of HDL receptor activity in liver.