Interaction of apolipoprotein B-containing lipoprotein secreted by Hep G2 cells with receptors for low-density lipoprotein.
Radioligand and immunoenzymatic techniques were used to characterize the receptor binding properties of apolipoprotein B-containing lipoprotein produced by HepG2 cell line (H-LpB). It was found that compared to plasma low-density lipoprotein (LDL), the interaction of H-LpB nonseparated from conditioned medium with normal fibroblasts was 6-8-times lower and only slightly exceeded the nonspecific binding of LDL modified by malondialdehyde, while the uptake of the indicated lipoproteins by LDL receptor-negative strain of fibroblasts were identical. The uptake of H-LpB by normal fibroblasts increased 1.5-2-times after isolation from the culture medium by immunoaffinity chromatography. The effect of isolation could be explained by the finding that apolipoprotein E-containing lipoprotein secreted by HepG2 cells effectively competed for the binding with LDL-receptors. The obtained results suggest that H-LpB produced by HepG2 cells is poorly recognized by the LDL-receptors.
Fuki
I V
IV
Institute of Experimental Cardiology, USSR Cardiology Research Center, Moscow.
Menschikov
G B
GB
Menschikowski
M
M
Adamova IYu
Repin
V S
VS
D001055:Apolipoproteins B / Q000032:analysis*; D001057:Apolipoproteins E / Q000032:analysis; D001667:Binding, Competitive; D006528:Carcinoma, Hepatocellular / Q000378:metabolism*; D005347:Fibroblasts / Q000378:metabolism; D006801:Humans; D008074:Lipoproteins / Q000737:chemistry / Q000378:metabolism*; D008077:Lipoproteins, LDL / Q000378:metabolism; D008113:Liver Neoplasms / Q000378:metabolism*; D011973:Receptors, LDL / Q000378:metabolism*; D014407:Tumor Cells, Cultured
D001055:Apolipoproteins B; D001057:Apolipoproteins E; D008074:Lipoproteins; D008077:Lipoproteins, LDL; D011973:Receptors, LDL