CeNS Colloquium

Prof. Heiner Linke
The Nanometer Structure Consortium and Division of Solid State Physics, Lund University

Molecular motors are true nanomachines that directly convert chemical energy into mechanical work. Motors such as kinesins, myosins, polymerases and ATP synthases are central to the function of cells, and these protein assemblies are vastly more sophisticated than currently achievable, man-made nanomechanical devices. My group is interested in the more fundamental aspects of how molecular motors work. Questions of interest include: How is random, thermal motion incorporated into efficient motor operation? How do the motors mechanical properties (such as stiffness) relate to motor performance? Are there general engineering tricks that we can learn from biology and apply to artificial nanomachines? After a general introduction to motors and to so-called ratchet models, I will present two projects that in different ways approach these questions. The first is a modeling project that focuses on myosin V, a bipedal walker for which detailed experimental data are available. We developed a well-constrained, coarse-grain, Brownian dynamics model that explicitly takes into account thermal motion of motor parts, and confirms that existing models do a good job of describing motor performance [1]. The second, experimental, project is an ongoing effort to build an artificial protein motor by combining de-novo peptide design and molecular biology [2]. I will describe the design and the status of experiment, as well as modeling results on how design details determine motor performance [3].

References:
[1] E. Craig and H. Linke, A mechanochemical model for myosin V Proc. Natl. Acad. Sci. USA 106, 18261 (2009).
[2] B. Bromley, N. Kuwada, M. Zuckermann, R. Donadini, L. Samii, G. Blab, G. Gemmen, B. Lopez, P. Curmi, N. R. Forde, D. N. Woolfson, and H. Linke, The Tumbleweed: Towards a synthetic protein motor. HFSP J. 3, 204 (2009).
[3] N. Kuwada, G. Blab, and H. Linke, A Master equation approach to modeling an articial protein motor arxiv.org/abs/1004.1114. submitted to J. Chem. Phys. (2010).