Ghiselli G, Crump W, Musanti R, Gotto A M
Baylor College of Medicine, Houston, TX.
Biochim Biophys Acta. 1990 May 1;1044(1):173-5. doi: 10.1016/0005-2760(90)90234-o.
Apolipoprotein A-IV (apo A-IV) is present in plasma associated to both HDL and as a complex with lipids that cannot be floated by ultracentrifugation at 1.21 g/ml density. Apo A-IV is likely an important molecular determinant in HDL binding to the liver. In this communication, data are presented supporting the view that a specific liver plasma membrane protein of Mr 95,000 is a constituent of the apo A-IV binding site. The protein was solubilized with CHAPS from purified rat liver plasma membranes and subjected to SDS-PAGE. Transblotted to nitrocellulose sheet could be identified as recognizing 125I-apo A-IV-DMPC by autoradiography. 125I-apo A-I-DMPC and radioiodinated rat apo E-poor HDL, also bound to the protein. Apo B-100 (as human LDL) and apo C-III did not bind. The protein identified is likely to be the same that has been previously identified by Graham and Oram [1987) J. Biol. Chem. 262, 7439-7442) as 'HDL receptor protein'.
载脂蛋白A-IV（apo A-IV）存在于血浆中，与高密度脂蛋白（HDL）相关联，并以一种不能在1.21 g/ml密度下通过超速离心漂浮的脂质复合物形式存在。Apo A-IV可能是HDL与肝脏结合的重要分子决定因素。在本通讯中，所呈现的数据支持这样一种观点，即一种分子量为95,000的特定肝细胞膜蛋白是apo A-IV结合位点的组成部分。该蛋白用CHAPS从纯化的大鼠肝细胞膜中溶解出来，并进行SDS-PAGE。转印到硝酸纤维素膜上后，通过放射自显影可鉴定为能识别125I-apo A-IV-DMPC。125I-apo A-I-DMPC和放射性碘化的大鼠低载脂蛋白E的HDL也与该蛋白结合。载脂蛋白B-100（作为人低密度脂蛋白）和载脂蛋白C-III不结合。所鉴定的该蛋白可能与先前由格雷厄姆和奥勒姆[1987年，《生物化学杂志》262卷，7439 - 7442页]鉴定为“HDL受体蛋白”的是同一种蛋白。
