紀要論文

光操作を用いたナトリウムイオン駆動力の動的変化の定量

QUANTIFICATION OF ION MOTIVE FORCE CONTROLED BY OPTPGENETICS

jpn

24368083

https://doi.org/10.15002/00025417

法政大学大学院理工学研究科

法政大学大学院紀要. 理工学研究科編

63

1

2

2022-03-24

Version of Record

The bacterial flagellar motor generates the rotational torque by the interactions between a rotor and multiple stator units. Each stator unit translocates the coupling ions, driven by ion motive force (IMF). The coupling ions known to be either protons or sodium ions, depending on the stator complexes. In Escherichia coli cells, wild type stator units MotA/MotB couple proton flux to generate the rotational torque. Chimeric stator units, PomA/PotB, can interact with a rotor of E. coli and couple sodium ions for torque generation. In this study, we controlled and quantified the sodium ion motive force (SMF) of E. coli cells. The SMF of the cells was dynamically manipulated using a light-driven sodium ion pump KR2 with excitation by irradiation of green light. To quantify the SMF accurately, we measured cytoplasmic sodium ion concentration and membrane potential by observing sodium green and TMRM, respectively. As a result, we showed that the increase in the speed of the PomAPotB motor when KR2 was expressed in E. coli cells could be explained by an increase in SMF, indicating that the speed of the motor varies linearly with IMF over a wide range.

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