Davies A O
Department of Medicine, Baylor College of Medicine, Houston, Texas 77030.
J Endocrinol Invest. 1988 Apr;11(4):239-45. doi: 10.1007/BF03350146.
The purpose of this study was to examine the quantitative relationship between the redox potential of a redox couplet and the alterations it induces in coupling of receptor occupation with enzyme activation. Normal neutrophil membrane preparations containing beta 2-adrenergic receptors were exposed to equimolar mixtures of the following redox couplets: ferrocyanide-ferricyanide, hemoglobin-methemoglobin, ascorbate-dehydroascorbate, lactate-pyruvate, glutathione ox-red, beta-hydroxybutyrate-acetoacetate, and NAD-NADH. There was a linear relationship between the redox potential of the couplets and the degree of change in coupling (p less than 0.001). The apparent redox potential of the high affinity complex was +0.30 +/- 0.093 V. The effect of lactate to uncouple beta-adrenergic receptors was partially blocked by preexposure to isoproterenol. Thus, high affinity state formation is regulated by redox couplets in a manner dependent on their redox potential.
本研究的目的是检测氧化还原电对的氧化还原电位与其诱导的受体占据与酶激活偶联变化之间的定量关系。将含有β2 - 肾上腺素能受体的正常中性粒细胞膜制剂暴露于以下氧化还原电对的等摩尔混合物中：亚铁氰化物 - 铁氰化物、血红蛋白 - 高铁血红蛋白、抗坏血酸 - 脱氢抗坏血酸、乳酸盐 - 丙酮酸盐、氧化型谷胱甘肽 - 还原型谷胱甘肽、β - 羟基丁酸 - 乙酰乙酸以及NAD - NADH。电对的氧化还原电位与偶联变化程度之间存在线性关系（p < 0.001）。高亲和力复合物的表观氧化还原电位为 +0.30 +/- 0.093 V。预先暴露于异丙肾上腺素可部分阻断乳酸使β - 肾上腺素能受体解偶联的作用。因此，高亲和力状态的形成受氧化还原电对的调节，其方式取决于它们的氧化还原电位。
