Pilizota Teuta, Bilyard Thomas, Bai Fan, Futai Masamitsu, Hosokawa Hiroyuki, Berry Richard M
Clarendon Laboratory, Department of Physics, University of Oxford, Oxford, United Kingdom.
Biophys J. 2007 Jul 1;93(1):264-75. doi: 10.1529/biophysj.106.091074. Epub 2007 Apr 13.
Optical tweezers are widely used for experimental investigation of linear molecular motors. The rates and force dependence of steps in the mechanochemical cycle of linear motors have been probed giving detailed insight into motor mechanisms. With similar goals in mind for rotary molecular motors we present here an optical trapping system designed as an angle clamp to study the bacterial flagellar motor and F(1)-ATPase. The trap position was controlled by a digital signal processing board and a host computer via acousto-optic deflectors, the motor position via a three-dimensional piezoelectric stage and the motor angle using a pair of polystyrene beads as a handle for the optical trap. Bead-pair angles were detected using back focal plane interferometry with a resolution of up to 1 degrees , and controlled using a feedback algorithm with a precision of up to 2 degrees and a bandwidth of up to 1.6 kHz. Details of the optical trap, algorithm, and alignment procedures are given. Preliminary data showing angular control of F(1)-ATPase and angular and speed control of the bacterial flagellar motor are presented.
光镊被广泛用于线性分子马达的实验研究。线性马达机械化学循环中步移的速率和力依赖性已得到探究，从而深入了解马达机制。出于对旋转分子马达的类似研究目的，我们在此展示一种设计为角度钳的光阱系统，用于研究细菌鞭毛马达和F(1)-ATP酶。通过声光偏转器，由数字信号处理板和主机控制阱的位置；通过三维压电平台控制马达的位置；使用一对聚苯乙烯珠作为光阱的手柄来控制马达的角度。使用背焦平面干涉测量法检测珠对角度，分辨率高达1度，并使用反馈算法进行控制，精度高达2度，带宽高达1.6千赫兹。文中给出了光阱、算法和对准程序的详细信息。还展示了关于F(1)-ATP酶角度控制以及细菌鞭毛马达角度和速度控制的初步数据。
