TCB Publications - Abstract
Hui Lu and Klaus Schulten. Steered molecular dynamics simulation of conformational changes of immunoglobulin domain I27 interpret atomic force microscopy observations. Chemical Physics, 247:141-153, 1999.
sandwich domain architecture and the function of this class of proteins. The proteins, linear segments of up to hundreds of domains, through strain induced shape changes, unfolding and refolding, maintain order and elasticity in cellular systems over a nearly tenfold length scale. In this paper we develop a steered molecular dynamics description of the response of the immunoglobulin domain I27 at the onset of domain unfolding in quantitative agreement with AFM observations. We show that if forces stronger than 50 pN are applied between the terminal ends, the two hydrogen bonds between the antiparallel A a B strands break with a concomitant 6 
elongation of the protein. If forces strong enough to unfold the domain are applied, the protein is halted in this initial extension until the set of all six hydrogen bonds connecting strands A' and G break simultaneously. This behavior is accounted for by a barrier separating folded states, the shape of which is consistent with AFM and denaturation data. We also demonstrate that steered molecular dynamics simulations which induce unfolding through slow pulling (speed 0.1 /ps) predict unfolding forces that are within a factor of two within force values extrapolated from AFM observations. Download Full Text
The manuscripts available on our site are provided for your personal use only and may not be retransmitted or redistributed without written permissions from the paper's publisher and author. You may not upload any of this site's material to any public server, on-line service, network, or bulletin board without prior written permission from the publisher and author. You may not make copies for any commercial purpose. Reproduction or storage of materials retrieved from this web site is subject to the U.S. Copyright Act of 1976, Title 17 U.S.C.
