Dynamic transition from $\alpha$-helices to $\beta$-sheets in polypeptide superhelices
Abstract
We carried out dynamic force manipulations on a variety of superhelical protein fragments from myosin, chemotaxis receptor, vimentin, fibrin, and phenylalanine zippers that vary in size and topology of their -helical packing. When stretched along the superhelical axis, all superhelices show elastic, plastic, and inelastic elongation regimes, and undergo a dynamic transition from the -helices to the -sheets, which marks the onset of plastic deformation. Using Abeyaratne-Knowles formulation of phase transitions, we developed a theory to model mechanical and kinetic properties of protein superhelices under mechanical non-equilibrium conditions and to map their energy landscapes. The theory was validated by comparing the simulated and theoretical force-strain spectra. Scaling laws for the elastic force and the force for -to- transition to plastic deformation can be used to rationally design new materials of required mechanical strength with desired balance between stiffness and plasticity.
Cite
@article{arxiv.1703.02922,
title = {Dynamic transition from $\alpha$-helices to $\beta$-sheets in polypeptide superhelices},
author = {Kirill A. Minin and Artem Zhmurov and Kenneth A. Marx and Prashant K. Purohit and Valeri Barsegov},
journal= {arXiv preprint arXiv:1703.02922},
year = {2017}
}