ABSTRACT
It is known that motor proteins convert a chemical energy into a mechanical motion (Lodish et al. 2007, Alberts et al. 2007, Howard 2001) [95, 4, 68]. In their work, biological molecular motors are involved in a large number of chemical reactions and in interactions with other biological molecules such as the cytoskeleton proteins, and with DNA, RNA, and other enzymes. The motors interact with different molecules and cellular structures via mechanical, electrostatic, hydrodynamic, and chemical forces. On top of this, it is always important to remember that motor proteins function in biological cells that are strongly non-equilibrium systems. These observations raise a lot of issues that need be analyzed and clarified if we want to understand mechanisms of motor proteins. Crucial questions are:
1. How can we rationalize all the observations quantitatively? 2. What does it mean to be in a system at equilibrium or out of equilibrium
and how important is it for molecular motors? 3. Why can chemical energy be transformed into mechanical work and
what is the efficiency of this process? 4. How does the participation in chemical processes influence the proper-
ties of motor proteins?
