Yamauchi K, Yamamoto T, Hayashi H, Koya S, Takikawa H, Toyoshima K, Horiuchi R
Biochem Biophys Res Commun. 1987 Aug 14;146(3):1485-92. doi: 10.1016/0006-291x(87)90817-5.
The complementary DNAs of the bovine liver membrane-associated 3,5,3'-triiodo-L-thyronine binding protein with 55 k-dalton (T3BP) were cloned and the nucleotide sequences were determined. Monospecific antibodies against T3BP were used to screen a bovine liver cDNA library in lambda gtll. We analyzed the sequences of two cloned T3BP cDNAs. The clones encoded a polypeptide of 510 amino acid residues, including a signal peptide of 20 amino acid. Northern blot analysis of bovine and human RNA showed that the mRNAs encoding T3BP are 2.7 kilobase in length. Amino acid sequence of N-terminal and other three peptides isolated from purified T3BP were found in the predicted amino acid sequence from the cDNA sequence. The predicted amino acid sequence is closely homologous (93%) with that of rat protein disulphide isomerase (EC 5.3.4.1), which catalyzes the isomerization of the protein disulphide bonds and has been shown to play an important role in post-translational regulation. The results suggest that T3BP and protein disulphide isomerase should be the same protein.
克隆了牛肝膜相关的55千道尔顿3,5,3'-三碘-L-甲状腺原氨酸结合蛋白（T3BP）的互补DNA，并测定了其核苷酸序列。使用针对T3BP的单特异性抗体筛选λgtll载体中的牛肝cDNA文库。我们分析了两个克隆的T3BP cDNA的序列。这些克隆编码一个由510个氨基酸残基组成的多肽，其中包括一个20个氨基酸的信号肽。对牛和人RNA的Northern印迹分析表明，编码T3BP的mRNA长度为2.7千碱基。从纯化的T3BP中分离出的N端氨基酸序列和其他三个肽段在cDNA序列预测的氨基酸序列中被发现。预测的氨基酸序列与大鼠蛋白质二硫键异构酶（EC 5.3.4.1）的序列高度同源（93%），该酶催化蛋白质二硫键的异构化，并已证明在翻译后调控中起重要作用。结果表明，T3BP和蛋白质二硫键异构酶应该是同一种蛋白质。
