中国物理B ›› 2005, Vol. 14 ›› Issue (9): 1745-1754.doi: 10.1088/1009-1963/14/9/010

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Symmetric linear potential and imperfect Brownian ratchet in molecular motor function

李防震, 胡匡祜, 苏万芳, 陈袆辰   

  1. Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
  • 收稿日期:2005-03-24 修回日期:2005-04-19 出版日期:2005-09-20 发布日期:2005-09-20
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant No 39970217).

Symmetric linear potential and imperfect Brownian ratchet in molecular motor function

Li Fang-Zhen (李防震), Hu Kuang-Hu (胡匡祜), Su Wan-Fang (苏万芳), Chen Yi-Chen (陈袆辰)   

  1. Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
  • Received:2005-03-24 Revised:2005-04-19 Online:2005-09-20 Published:2005-09-20
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant No 39970217).

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摘要： Biomolecular motors are tiny engines that transport materials at the microscopic level within biological cells. In recent years, Elston and Peskin et al have investigated the effect of the elastic properties of the tether that connects the motor to its cargo at the speed of the motor. In this paper we extend their work and present a tether in the form of symmetric linear potential.Our results show that when the driving mechanism is an imperfect Brownian ratchet, the average speed decreases as the stiffness of the tether increases in the limit of large motor diffusion coefficient, which is similar to the results of Elston and Peskin.However, a threshold for the stiffness of the tether connecting the motor to its cargo is found in our model. Only when the tether is stiffer than the threshold can the motor and its cargo function co-operatively, otherwise, the motor and its cargo depart from each other. This result is more realistic than that of the spring model of Elston and Peskin.

关键词: biomolecular motors, Brownian ratchet, protein flexibility, symmetric linear potential

Abstract: Biomolecular motors are tiny engines that transport materials at the microscopic level within biological cells. In recent years, Elston and Peskin et al have investigated the effect of the elastic properties of the tether that connects the motor to its cargo at the speed of the motor. In this paper we extend their work and present a tether in the form of symmetric linear potential.Our results show that when the driving mechanism is an imperfect Brownian ratchet, the average speed decreases as the stiffness of the tether increases in the limit of large motor diffusion coefficient, which is similar to the results of Elston and Peskin.However, a threshold for the stiffness of the tether connecting the motor to its cargo is found in our model. Only when the tether is stiffer than the threshold can the motor and its cargo function co-operatively, otherwise, the motor and its cargo depart from each other. This result is more realistic than that of the spring model of Elston and Peskin.

Key words: biomolecular motors, Brownian ratchet, protein flexibility, symmetric linear potential

中图分类号:  (Motor proteins (myosin, kinesin dynein))

  • 87.16.Nn
87.16.Uv (Active transport processes) 87.15.La (Mechanical properties) 02.30.Jr (Partial differential equations)