Im M J, Holzhöfer A, Böttinger H, Pfeuffer T, Helmreich E J
Department of Physiological Chemistry, University of Würzburg, Medical School, FRG.
FEBS Lett. 1988 Jan 25;227(2):225-9. doi: 10.1016/0014-5793(88)80903-7.
The role of the beta gamma-subunits in the interaction of G-proteins was examined with beta 1-adrenoceptors purified from turkey erythrocytes and pure beta gamma-subunits prepared from turkey erythrocytes and bovine brain. On a non-denaturing polyacrylamide gel, the mobility of beta gamma-subunits was increased when incubated with beta 1-adrenoceptor and the beta 1-adrenergic agonist 1-(-)-isoproterenol, whereas on incubation with the antagonist 1-alprenolol the mobility was unchanged. Furthermore, the beta 1-adrenoceptor was retarded on a Sephadex G-50 column equilibrated with beta gamma-subunits and agonist. No retardation occurred in the presence of antagonist. These data suggest a direct interaction of activated beta 1-adrenoceptors with isolated beta gamma-subunits of G-proteins.
利用从火鸡红细胞中纯化得到的β1-肾上腺素能受体以及从火鸡红细胞和牛脑中制备的纯βγ亚基,研究了βγ亚基在G蛋白相互作用中的作用。在非变性聚丙烯酰胺凝胶上,当βγ亚基与β1-肾上腺素能受体及β1-肾上腺素能激动剂1-(-)-异丙肾上腺素一起孵育时,其迁移率增加,而与拮抗剂1-阿普洛尔孵育时迁移率不变。此外,在以βγ亚基和激动剂平衡的葡聚糖G-50柱上,β1-肾上腺素能受体的迁移受到阻滞。在存在拮抗剂的情况下则没有阻滞现象。这些数据表明活化的β1-肾上腺素能受体与G蛋白的分离βγ亚基之间存在直接相互作用。