PROTON-TRANSFER IS RATE-LIMITING FOR TRANSLOCATION OF PRECURSOR PROTEINS BY THE ESCHERICHIA-COLI TRANSLOCASE
PROTON-TRANSFER IS RATE-LIMITING FOR TRANSLOCATION OF PRECURSOR PROTEINS BY THE ESCHERICHIA-COLI TRANSLOCASE
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DOI：
10.1073/pnas.88.6.2471
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发表时间：
1991-03-01
影响因子：
11.1
通讯作者：
WICKNER, W
中科院分区：
文献类型：
--
作者：
DRIESSEN, AJM;WICKNER, W
质子动力刺激体内的移位，在粗略的体外反应中，以及在纯化、重组的反应中。转位活性是膜内表面pH的函数。跨膜pH梯度和跨膜电位都刺激易位。当施加质子力时，ProOmpA前蛋白的晚期易位中间体在没有ATP的情况下完成其易位。这种移位的完成被相对于水的氢氧化物中的>；3倍的延迟，这表明移位涉及限速步骤中的质子转移反应。
The protonmotive force stimulates translocation in vivo, in crude in vitro reactions, and in a purified, reconstituted reaction. Translocation activity is a function of the pH at the inner face of the membrane. Both the transmembrane pH gradient and the transmembrane electrical potential stimulate translocation. A late-stage translocation intermediate of the proOmpA preprotein completes its translocation in the absence of ATP when a protonmotive force is imposed. This completion of translocation is retarded by a factor of > 3 in deuterium oxide relative to water, demonstrating that translocation involves proton-transfer reactions in rate-limiting steps.