Hammond G L, Underhill D A, Smith C L, Goping I S, Harley M J, Musto N A, Cheng C Y, Bardin C W
FEBS Lett. 1987 May 4;215(1):100-4. doi: 10.1016/0014-5793(87)80121-7.
We have sequenced a cDNA for sex hormone-binding globulin (SHBG) isolated from a phage lambda gt11 human liver cDNA library. The library was screened with a radiolabeled rat androgen-binding protein (ABP) cDNA, and the abundance of SHBG cDNAs was 1 in 750,000 plaques examined. The largest human SHBG cDNA (1194 base-pairs) contained a reading frame for 381 amino acids. This comprised 8 amino acids of a signal peptide followed by 373 residues starting with the known NH2-terminal sequence of human SHBG, and ending with a termination codon. The predicted polypeptide Mr of SHBG is 40,509, and sites of attachment of one O-linked (residue 7) and two N-linked oligosaccharide (residues 351 and 367) chains were identified. Purified SHBG was photoaffinity-labeled with delta 6-[3H]testosterone and cleaved with trypsin. The labeled tryptic fragment was isolated by reverse-phase HPLC, and its NH2-terminal sequence was determined. The results suggest that a portion of the steroid-binding domain of SHBG is located between residue 296 and the 35 predominantly hydrophilic residues at the C-terminus of the protein.
我们对从噬菌体λgt11人肝脏cDNA文库中分离出的性激素结合球蛋白（SHBG）的cDNA进行了测序。用放射性标记的大鼠雄激素结合蛋白（ABP）cDNA筛选该文库，在所检测的750,000个噬菌斑中，SHBG cDNA的丰度为1个。最大的人SHBG cDNA（1194个碱基对）包含一个编码381个氨基酸的阅读框。它由一个信号肽的8个氨基酸以及从人SHBG已知的NH2末端序列开始的373个残基组成，并以一个终止密码子结束。预测的SHBG多肽Mr为40,509，并确定了一条O-连接（第7位残基）和两条N-连接寡糖（第351位和第367位残基）链的连接位点。用δ6-[3H]睾酮对纯化的SHBG进行光亲和标记，并用胰蛋白酶切割。通过反相高效液相色谱法分离标记的胰蛋白酶片段，并测定其NH2末端序列。结果表明，SHBG类固醇结合结构域的一部分位于第296位残基与该蛋白C末端的35个主要亲水残基之间。
