Wright T L, Lysenko N, Ockner R K, Weisiger R A
Hepatology. 1987 Mar-Apr;7(2):294-301. doi: 10.1002/hep.1840070214.
The hepatitis B virus binds avidly to albumin polymers which in turn may mediate the initial binding of viral particles to the liver cell. However, the interaction of albumin polymers with the liver remains poorly characterized, and the possibility that hepatic binding reflects an artifact of polymerization with glutaraldehyde has not been excluded. We therefore characterized the binding of 125I-labeled natural and synthetic albumin polymers to suspensions of rat hepatocytes. Saturable binding was demonstrated for all preparations of monomeric and polymeric albumin studied. Glutaraldehyde-polymerized albumin (mean polymerization number = 15) bound much more avidly than naturally occurring albumin polymers (mostly dimers and trimers) or monomeric albumin. Competition between monomer and synthetic polymer was not observed. Reduction of free aldehyde groups on the synthetic polymer decreased nonsaturable binding without affecting saturable binding. Autoradiography confirmed binding of polyalbumin to hepatic parenchymal cells. Glutaraldehyde-polymerized ovalbumin, a protein unrelated to serum albumin, also bound hepatocytes saturably. We conclude that hepatic binding of synthetic albumin polymers is not due to residual aldehyde groups on the polymer and is much more avid than for natural polymer. This difference may reflect the higher degree of polymerization or chemical modification of the synthetic polymer. The hepatic binding sites for synthetic polymer appear distinct from those previously described for monomeric albumin and may not be specific for albumin.
乙肝病毒能紧密结合白蛋白聚合物，而白蛋白聚合物反过来可能介导病毒颗粒与肝细胞的初始结合。然而，白蛋白聚合物与肝脏之间的相互作用仍未得到充分表征，且肝脏结合反映与戊二醛聚合的人为产物这种可能性尚未排除。因此，我们对125I标记的天然和合成白蛋白聚合物与大鼠肝细胞悬液的结合进行了表征。对所研究的所有单体和聚合白蛋白制剂均证明了可饱和结合。戊二醛聚合的白蛋白（平均聚合数 = 15）比天然存在的白蛋白聚合物（大多为二聚体和三聚体）或单体白蛋白结合得更为紧密。未观察到单体与合成聚合物之间的竞争。合成聚合物上游离醛基的减少降低了非饱和结合，而不影响饱和结合。放射自显影证实了多聚白蛋白与肝实质细胞的结合。戊二醛聚合的卵清蛋白，一种与血清白蛋白无关的蛋白质，也能与肝细胞发生饱和结合。我们得出结论，合成白蛋白聚合物的肝脏结合并非由于聚合物上残留的醛基，且比天然聚合物结合更为紧密。这种差异可能反映了合成聚合物更高的聚合度或化学修饰。合成聚合物的肝脏结合位点似乎与先前描述的单体白蛋白的结合位点不同，且可能并非白蛋白特异性的。
