Sugiyama Y, Yamada T, Kaplowitz N
Biochim Biophys Acta. 1982 Dec 20;709(2):342-52. doi: 10.1016/0167-4838(82)90477-0.
Previously, all organic anion binding activity in the Y protein (ligandin-containing) fraction of rat liver cytosol has been attributed to the glutathione S-transferases. Gel filtration on Sephadex G-75 superfine has resolved the Y protein fraction into organic anion-binding fractions of two distinct molecular weights: (a) Mr 45 000 containing the glutathione S-transferases, and (b) Mr 35 000 referred to as Y'. Two proteins (Dv and D1) were purified from the Y' fraction. Dv is a basic protein consisting of four subunits of Mr 8000-9000 and selectively binds 1-anilino-8-naphthalene sulfonate and sulfobromophthalein. D1 is a monomer (Mr 40 000) which exhibits high affinity binding for Rose Bengal. Dv protein bound a broad spectrum of organic anions. Antibody raised in rabbits to rat Dv showed no cross-reactivity with purified glutathione S-transferases A, B, or C. Thus, we have identified organic anion-binding proteins which are unrelated to the glutathione S-transferases, but which were previously associated with the crude Y-fraction. The relative abundance of these proteins and their binding characteristics suggest their role in hepatic organic anion transport.
以往，大鼠肝细胞溶质Y蛋白（含配体蛋白）部分中的所有有机阴离子结合活性均被认为归因于谷胱甘肽S - 转移酶。用超细葡聚糖凝胶G - 75进行凝胶过滤已将Y蛋白部分分离为两种不同分子量的有机阴离子结合部分：（a）分子量为45000的部分，含有谷胱甘肽S - 转移酶；（b）分子量为35000的部分，称为Y'。从Y'部分纯化出两种蛋白质（Dv和D1）。Dv是一种碱性蛋白，由四个分子量为8000 - 9000的亚基组成，可选择性结合1 - 苯胺基 - 8 - 萘磺酸盐和磺溴酞。D1是一种单体（分子量为40000），对孟加拉玫瑰红表现出高亲和力结合。Dv蛋白能结合多种有机阴离子。用兔制备的抗大鼠Dv抗体与纯化的谷胱甘肽S - 转移酶A、B或C无交叉反应。因此，我们鉴定出了与谷胱甘肽S - 转移酶无关但以前与粗制Y部分相关的有机阴离子结合蛋白。这些蛋白的相对丰度及其结合特性表明它们在肝脏有机阴离子转运中的作用。
