Ketterer B, Tipping E, Hackney J F, Beale D
Biochem J. 1976 Jun 1;155(3):511-21. doi: 10.1042/bj1550511.
A protein of S20,W 1.6S and mol.wt. 14000, which binds covalently a metabolite of the aminoazodye carcinogen NN-dimethyl-4-amino-3'-methylazobenzene, was isolated from rat liver cytosol from both carcinogen-treated and normal rats. The protein binds non-covalently palmitoyl-CoA, fatty acids, bilirubin, sex steroids and their sulphates, bile acids and salts, bromosulphophthalein, diethylstilboestrol and 20-methylcholanthrene with a wide range of affinities. The protein is isolated as three components with isoelectric points of 5.0, 5.9 and 7.6 by a method involving isoelectric focusing. All three components have closely similar amino acid analyses, tryptic-peptide 'maps' and u.v. spectra. Each single component redistributes into all three on further electrophoresis. However, the three forms differ in their binding characteristics, the form of pI 7.6 having much the highest affinity for compounds bound non-covalently. The protein was identified immunologically in rat liver, small intestine, adipose tissue, skeletal muscle, myocardium and testis. The protein was compared with other hepatic binding-protein preparations of similar molecular weight.
从经致癌物处理的大鼠和正常大鼠的肝脏胞质溶胶中分离出一种S20、W 1.6S且分子量为14000的蛋白质，它能与氨基偶氮染料致癌物NN - 二甲基 - 4 - 氨基 - 3'-甲基偶氮苯的一种代谢产物共价结合。该蛋白质能以广泛的亲和力非共价结合棕榈酰辅酶A、脂肪酸、胆红素、性类固醇及其硫酸盐、胆汁酸和盐、溴磺酚酞、己烯雌酚和20 - 甲基胆蒽。通过等电聚焦方法，该蛋白质被分离为三种成分，其等电点分别为5.0、5.9和7.6。所有这三种成分的氨基酸分析、胰蛋白酶肽“图谱”和紫外光谱都非常相似。在进一步电泳时，每种单一成分都会重新分布为这三种成分。然而，这三种形式的结合特性有所不同，等电点为7.6的形式对非共价结合的化合物具有最高的亲和力。在大鼠肝脏、小肠、脂肪组织、骨骼肌、心肌和睾丸中通过免疫方法鉴定出了这种蛋白质。将该蛋白质与其他分子量相似的肝脏结合蛋白制剂进行了比较。
