Covalent crosslinking of human chorionic gonadotropin to its receptor in rat testes.
Covalent crosslinking of human chorionic gonadotropin to its receptor in rat testes.
复制标题
人绒毛膜促性腺激素与其在大鼠睾丸中的受体的共价交联。
DOI：
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发表时间：
1981
影响因子：
11.1
通讯作者：
P. Fishman
中科院分区：
文献类型：
--
作者：
R. V. Rebois;F. Omedeo;R. Brady;P. Fishman
The bifunctional crosslinking reagents disuccinimidyl suberate and dithiobis(succinimidyl propionate) were used to attach 125I-labeled human chorionic gonadotropin (125I-hCG) covalently to rat testicular membranes. The extent of crosslinking was dependent on time and concentration; routinely, 30% of the specifically bound hormone was covalently linked to the membranes in the presence of 0.5 mM crosslinking reagent when incubated at 25 degrees C for 15 min. Excess unlabeled hCG blocked the crosslinking of 125I-hCG to the membranes. When solubilized with Triton X-100 and analyzed by sucrose density gradient centrifugation, both the native and the crosslinked hormone-receptor complex sedimented with an apparent Mr of 220,000. Thus, the receptor itself would have Mr 180,000. When the crosslinked complex was analyzed by sodium dodecyl sulfate/polyacrylamide gel electrophoresis, the predominant species had a Mr of 123,000 and appeared to represent the labeled alpha subunit of hCG covalently linked to a membrane component. The Mr of this receptor component would be 100,000, a value approximately half that of the Triton X-100-solubilized receptor. Thus, the membrane receptor for hCG may consist of a dimer of two binding subunits or a binding subunit associated with one or more additional subunits that might play a coupling or regulatory function.
