BIOPHYSICAL THEORY AND MODELING |
Inferring the diameter of a biopolymer from its stretching response
Ngo Minh Toan 1, Davide Marenduzzo 2* and Cristian Micheletti 1
1 SISSA
2 Oxford University
* To whom correspondence should be addressed. E-mail: davide{at}thphys.ox.ac.uk.
Submitted on December 16, 2004
Revised on January 24, 2005
Accepted on 4 April 2005
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Abstract |
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We investigate the stretching response of a thick polymer model by means of extensive stochastic simulations. The computational results are synthesized in an analytic expression that characterizes how the force versus elongation curve depends on the polymer structural parameters: its thickness and granularity (spacing of the monomers). The expression is used to analyze experimental data for the stretching of various different types of biopolymers: polypeptides, polysaccharides and nucleic acids. Besides recovering elastic parameters (such as the persistence length) that are consistent with those obtained from standard entropic models, the approach allows to extract viable estimates for the polymers diameter and granularity. This shows that the basic structural polymer features have such a profound impact on the elastic behaviour that they can be recovered with the sole input of stretching measurements.
Key Words:
Stretching of biopolymers, models for thick polymers, stochastic (Monte Carlo) simulations
