Binding properties of solubilized gonadotropin-releasing hormone receptor: role of carboxylic groups.
Binding properties of solubilized gonadotropin-releasing hormone receptor: role of carboxylic groups.
复制标题
溶解的促性腺激素释放激素受体的结合特性：羧基的作用。
作者：
E. Hazum
研究了促性腺激素释放激素（GnRH）超活性激动剂125 I-布舍瑞林与可溶性GnRH受体的相互作用。在4 ℃下，125 I-布舍瑞林与溶解的GnRH受体的特异性结合最高，孵育2 h后达到平衡。在4 ℃或22 ℃下保持60 min时，可溶性受体保留100%的原始结合活性。一价和二价阳离子以浓度依赖性方式抑制125 I-布舍瑞林与溶解的GnRH受体的结合。一价阳离子需要比二价阳离子更高的浓度来抑制结合。由于二价阳离子内的效力的顺序与它们与二羧酸化合物的缔合常数的顺序相同，因此建议受体中至少有两个羧基参与激素的结合。唾液酸残基的羧基不是GnRH结合的绝对必需基团，因为125 I-布舍瑞林与溶解的GnRH受体的结合仅受到神经氨酸酶和麦胚凝集素预处理的轻微影响。发现多聚赖氨酸刺激促黄体生成素（LH）释放垂体细胞培养物具有相同的功效GnRH表明，简单的电荷相互作用可以诱导LH的释放。根据这些结果，我们提出，形成的驱动力的受体复合物是带正电荷的氨基酸精氨酸在位置8和羧基之间的离子相互作用的结合位点。
The interaction of 125I-buserelin, a superactive agonist of gonadotropin-releasing hormone (GnRH), with solubilized GnRH receptor was studied. The highest specific binding of 125I-buserelin to solubilized GnRH receptor is evident at 4 degrees C, and equilibrium is reached after 2 h of incubation. The soluble receptor retained 100% of the original binding activity when kept at 4 or 22 degrees C for 60 min. Mono- and divalent cations inhibited, in a concentration-dependent manner, the binding of 125I-buserelin to solubilized GnRH receptor. Monovalent cations require higher concentrations than divalent cations to inhibit the binding. Since the order of potency within the divalent cations was identical with that of their association constants to dicarboxylic compounds, it is suggested that there are at least two carboxylic groups of the receptor that participate in the binding of the hormone. The carboxyl groups of sialic acid residues are not absolutely required for GnRH binding since the binding of 125I-buserelin to solubilized GnRH receptor was only slightly affected by pretreatment with neuraminidase and wheat germ agglutinin. The finding that polylysines stimulate luteinizing hormone (LH) release from pituitary cell cultures with the same efficacy as GnRH suggests that simple charge interactions can induce LH release. According to these results, we propose that the driving force for the formation of the hormone-receptor complex is an ionic interaction between the positively charged amino acid arginine in position 8 and the carboxyl groups in the binding site.
牛垂体质膜促性腺激素释放激素受体的溶解。
影响因子：
4.8
作者：
Perrin,MH;Haas,Y;Rivier,JE;Vale,WW
通讯作者：
Vale,WW
影响因子：
4.8
作者：
Conn,PM;Rogers,DC;Seay,SG;Staley,D
通讯作者：
Staley,D