Anteneodo C, Louro S R, Wajnberg E
Centro Brasileiro de Pesquisas Físicas, Rio de Janeiro, Brazil.
Biochim Biophys Acta. 1996 Jun 11;1281(2):150-6. doi: 10.1016/0005-2736(95)00291-x.
Alkanols and tertiary amine derivative local anesthetics modify the activity of Ca(2+)-ATPase. In order to investigate the primary binding sites, associated to the functional changes, sarcoplasmic reticulum (SR) Ca(2+)-ATPase was labeled with maleimide derivative spin labels which bind covalently to SH groups of cysteine residues and allow to probe the regions of the protein close to those residues. The EPR measurements showed motional constraints induced by drug-treatment which indicate changes in the enzyme dynamics and structure. n-Alkanols are shown to affect some of the protein-bound labels by restricting their motion. There is, however, no correlation between the functional effects and the observed motional restriction, in the sense that concentrations of the different alcohols leading to the same functional effects do not induce the same degree of restriction. Dibucaine and tetracaine at functional relevant concentrations also restrict the movement of protein bound labels. But, in this case, correlation between spectral changes and functional effects is observed.
链烷醇和叔胺衍生物局部麻醉药会改变Ca(2+)-ATP酶的活性。为了研究与功能变化相关的主要结合位点，用马来酰亚胺衍生物自旋标记对肌浆网（SR）Ca(2+)-ATP酶进行标记，该自旋标记与半胱氨酸残基的SH基团共价结合，并能探测蛋白质中靠近这些残基的区域。电子顺磁共振测量显示药物处理诱导了运动限制，这表明酶的动力学和结构发生了变化。正链烷醇通过限制一些与蛋白质结合的标记的运动来影响它们。然而，在不同醇类浓度导致相同功能效应却不诱导相同程度限制的意义上，功能效应与观察到的运动限制之间没有相关性。在功能相关浓度下，丁卡因和丁哌卡因也会限制与蛋白质结合的标记的运动。但是，在这种情况下，观察到了光谱变化与功能效应之间的相关性。
