Subunits of luteinizing hormone-human chorionic gonadotropin receptor from bovine corpora lutea.
Subunits of luteinizing hormone-human chorionic gonadotropin receptor from bovine corpora lutea.
复制标题
来自牛黄体的黄体生成激素-人绒毛膜促性腺激素受体的亚基。
DOI：
10.1021/bi00372a024
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发表时间：
1986
期刊：
影响因子：
2.9
通讯作者：
P. Rathnam
中科院分区：
文献类型：
--
作者：
B. Saxena;B. Dattatreyamurty;H. Ota;V. Milkov;P. Rathnam
从牛黄体中分离出一批24 mg促黄体生成素-人绒毛膜促性腺激素（LH-hCG）受体。LH-hCG受体与hCG有特异性结合。该受体-hCG复合物激活了从兔肝中分离的调节性Ns蛋白，该调节性Ns蛋白又在体外刺激腺苷酸环化酶将ATP转化为cAMP，证明了纯化的LH-hCG受体的生物活性。用2%十二烷基硫酸钠（SDS）处理LH-hCG受体以制备分子量（Mr）280 K二聚体，并用50 mM二硫苏糖醇（DTT）处理以制备Mr 120 K单体和Mr 85 K和38 K亚基。由于单体和亚基之间的二硫键的再结合，从凝胶过滤柱中回收了各种分子量的低聚物。因此，受体单体也解离成亚基的先生85 K和38 K的还原-S-S-键与50 mM DTT在2% SDS和烷基化的巯基在100 mM N-乙基-马来酰亚胺的存在下。通过Ultrogel AcA-44和Sephadex G-75柱的凝胶过滤分离亚基。纯化的烷基化亚基85 K和38 K的产量分别为1.8和1.5毫克。每个亚基在SDS-聚丙烯酰胺凝胶电泳中作为单一实体迁移。MR 120 K受体的单体与125 I-hCG特异性结合，表明它是受体的最小分子量功能单元。Mr 85 K和38 K亚基与125 I-hCG结合，不能被未标记的hCG取代。（250字处删节）
A batch of 24 mg of luteinizing hormone-human chorionic gonadotropin (LH-hCG) receptor was isolated from bovine corpora lutea. The LH-hCG receptor showed specific binding with hCG. The receptor-hCG complex activated the regulatory Ns protein isolated from rabbit liver, which in turn stimulated adenylate cyclase to convert ATP into cAMP in vitro, attesting to the biological activity of the purified LH-hCG receptor. The LH-hCG receptor was treated with 2% sodium dodecyl sulfate (SDS) to prepare the molecular weight (Mr) 280K dimer and with 50 mM dithiothreitol (DTT) to prepare the Mr 120K monomer and subunits of Mr 85K and 38K. Oligomers of various molecular weights were recovered from gel filtration columns due to the reassociation of disulfide bonds between monomers and subunits. Hence, the receptor monomer was also dissociated into subunits of Mr 85K and 38K by reduction of -S-S-bonds with 50 mM DTT in 2% SDS and alkylation of sulfhydryl groups in the presence of 100 mM N-ethyl-maleimide. The subunits were separated by gel filtration through columns of Ultrogel AcA-44 and Sephadex G-75. The yields of the purified alkylated subunits of Mr 85K and 38K were 1.8 and 1.5 mg, respectively. Each subunit migrated as a single entity in SDS-polyacrylamide gel electrophoresis. The monomer of the receptor of Mr 120K showed specific binding with 125I-hCG, suggesting it to be the minimum molecular weight functional unit of the receptor. The Mr 85K and 38K subunits bound 125I-hCG, which could not be displaced with unlabeled hCG.(ABSTRACT TRUNCATED AT 250 WORDS)