BIOPHYSICAL THEORY AND MODELING |
Simulation of the Mechanical Strength of a Single Collagen Molecule
Pieter in 't Veld 1 and Mark J. Stevens 1*
1 Sandia National Laboratories
* To whom correspondence should be addressed. E-mail: msteve{at}sandia.gov.
Submitted on August 28, 2007
Revised on October 3, 2007
Accepted on 16 January 2008
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Abstract |
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We perform atomistic simulations on a single collagen molecule to determine its intrinsic molecular strength. A tensile pull simulation to determine the tensile strength and Young's modulus is performed, and a simulation that separates two of the three helices of collagen examines the internal strength of the molecule. The magnitude of the calculated tensile forces is consistent with the strong forces of bond stretching and angle bending that are involved in the tensile deformation. The triple helix unwinds with increasing tensile force. Pulling apart the triple helix has a smaller, oscillatory force. The oscillations are due to the sequential separation of the hydrogen-bonded helices. The force rises due to reorienting the residues in the direction of the separation force. The force drop occurs once hydrogen bond between residues on different helices break and and the residues separate.
Key Words:
collagen, mechanics, molecular dynamics, simulation, single molecules
