Santos-Sacchi J, Wu M
Sections of Otolaryngology and Neurobiology, Yale University School of Medicine, New Haven, CT 06510, USA. joseph.santos-sacchi@ yale.edu
J Membr Biol. 2004 Jul 15;200(2):83-92. doi: 10.1007/s00232-004-0699-2.
Outer hair cells from the mamma*lian cochlea are mechanically active cells that rely on charged voltage sensors within their lateral plasma membrane to gate the integral membrane motor protein, prestin, into one of two area states. Here we use protein and lipid reactive reagents to probe the influence of these bilayer components on motor-induced nonlinear membrane capacitance. Of the protein-reactive reagents tested, cross-linking and sulfhydryl reagents were most effective in altering steady state and time-varying motor activity. Of the lipid-altering agents, chloroform and HePC were most effective. Chloroform, in particular, drastically modified the susceptibility of the motor to prior voltage (initial conditions). Our data suggest that outer hair cell motor activity derives substantially from interactions with its lipid environment.
哺乳动物耳蜗的外毛细胞是机械活性细胞，它们依靠其外侧质膜内的带电电压传感器，将整合膜运动蛋白—— prestin 门控到两种区域状态之一。在这里，我们使用蛋白质和脂质反应试剂来探究这些双层成分对运动诱导的非线性膜电容的影响。在所测试的蛋白质反应试剂中，交联剂和巯基试剂在改变稳态和时变运动活性方面最为有效。在脂质改变剂中，氯仿和 HePC 最为有效。特别是氯仿，它极大地改变了运动蛋白对先前电压（初始条件）的敏感性。我们的数据表明，外毛细胞的运动活性很大程度上源于与脂质环境的相互作用。
