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Title: X-ray diffraction from nonuniformly stretched helical molecules

Abstract

The fibrous proteins in living cells are exposed to mechanical forces interacting with other subcellular structures. X-ray fiber diffraction is often used to assess deformation and movement of these proteins, but the analysis has been limited to the theory for fibrous molecular systems that exhibit helical symmetry. However, this approach cannot adequately interpret X-ray data from fibrous protein assemblies where the local strain varies along the fiber length owing to interactions of its molecular constituents with their binding partners. To resolve this problem a theoretical formulism has been developed for predicting the diffraction from individual helical molecular structures nonuniformly strained along their lengths. This represents a critical first step towards modeling complex dynamical systems consisting of multiple helical structures using spatially explicit, multi-scale Monte Carlo simulations where predictions are compared with experimental data in a `forward' process to iteratively generate ever more realistic models. Here the effects of nonuniform strains and the helix length on the resulting magnitude and phase of diffraction patterns are quantitatively assessed. Examples of the predicted diffraction patterns of nonuniformly deformed double-stranded DNA and actin filaments in contracting muscle are presented to demonstrate the feasibly of this theoretical approach.

Authors:
; ;
Publication Date:
Research Org.:
Argonne National Lab. (ANL), Argonne, IL (United States). Advanced Photon Source (APS)
Sponsoring Org.:
NIHNIGMS
OSTI Identifier:
1400298
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Crystallography (Online); Journal Volume: 49; Journal Issue: 3
Country of Publication:
United States
Language:
ENGLISH
Subject:
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY

Citation Formats

Prodanovic, Momcilo, Irving, Thomas C., and Mijailovich, Srboljub M. X-ray diffraction from nonuniformly stretched helical molecules. United States: N. p., 2016. Web. doi:10.1107/S1600576716003757.
Prodanovic, Momcilo, Irving, Thomas C., & Mijailovich, Srboljub M. X-ray diffraction from nonuniformly stretched helical molecules. United States. doi:10.1107/S1600576716003757.
Prodanovic, Momcilo, Irving, Thomas C., and Mijailovich, Srboljub M. Mon . "X-ray diffraction from nonuniformly stretched helical molecules". United States. doi:10.1107/S1600576716003757.
@article{osti_1400298,
title = {X-ray diffraction from nonuniformly stretched helical molecules},
author = {Prodanovic, Momcilo and Irving, Thomas C. and Mijailovich, Srboljub M.},
abstractNote = {The fibrous proteins in living cells are exposed to mechanical forces interacting with other subcellular structures. X-ray fiber diffraction is often used to assess deformation and movement of these proteins, but the analysis has been limited to the theory for fibrous molecular systems that exhibit helical symmetry. However, this approach cannot adequately interpret X-ray data from fibrous protein assemblies where the local strain varies along the fiber length owing to interactions of its molecular constituents with their binding partners. To resolve this problem a theoretical formulism has been developed for predicting the diffraction from individual helical molecular structures nonuniformly strained along their lengths. This represents a critical first step towards modeling complex dynamical systems consisting of multiple helical structures using spatially explicit, multi-scale Monte Carlo simulations where predictions are compared with experimental data in a `forward' process to iteratively generate ever more realistic models. Here the effects of nonuniform strains and the helix length on the resulting magnitude and phase of diffraction patterns are quantitatively assessed. Examples of the predicted diffraction patterns of nonuniformly deformed double-stranded DNA and actin filaments in contracting muscle are presented to demonstrate the feasibly of this theoretical approach.},
doi = {10.1107/S1600576716003757},
journal = {Journal of Applied Crystallography (Online)},
number = 3,
volume = 49,
place = {United States},
year = {Mon Apr 18 00:00:00 EDT 2016},
month = {Mon Apr 18 00:00:00 EDT 2016}
}