Pre-transition effects mediate forces of assembly between transmembrane proteins
Abstract
We present a mechanism for a generic and powerful force of assembly and mobility for transmembrane proteins in lipid bilayers. This force is a pre-transition (or pre-melting) effect for the first-order transition between ordered and disordered phases in the host membrane. Using large scale molecular simulation, we show that a protein with hydrophobic thickness equal to that of the disordered phase embedded in an ordered bilayer stabilizes a microscopic order-disorder interface, and the stiffness of that interface is finite. When two such proteins approach each other, they assemble because assembly reduces the net interfacial free energy. In analogy with the hydrophobic effect, we refer to this phenomenon as the "orderphobic effect". The effect is mediated by proximity to the order-disorder phase transition and the size and hydrophobic mismatch of the protein. The strength and range of forces arising from the orderphobic effect are significantly larger than those that could arise from membrane elasticity for the membranes we examine.
Cite
@article{arxiv.1506.04298,
title = {Pre-transition effects mediate forces of assembly between transmembrane proteins},
author = {Shachi Katira and Kranthi K. Mandadapu and Suriyanarayanan Vaikuntanathan and Berend Smit and David Chandler},
journal= {arXiv preprint arXiv:1506.04298},
year = {2016}
}
Comments
Combined the previously published arXiv papers (arxiv:1506.04298 and arxiv:1506.04310) into the single paper after addressing comments from colleagues. The first order nature of the order-disorder phase transition is included in this paper. The title is altered to accommodate the changes in the paper