School Seminars and Colloquia

Role of conformational entropy in force-induced bio-polymer unfolding

Statistical Mechanics/Combinatorics Seminar

by Professor Anthony Guttmann

Institution: Department of Mathematics & Statistics, The University of Melbourne
Date: Thu 14th September 2006
Time: 3:15 PM
Location: Sisalkraft Theatre, Architecture (Ground floor), The University of Melbourne

Abstract: A statistical mechanical description of flexible and semiflexible polymer chains in a poor solvent is developed in the constant-force and constant-distance ensembles. We predict the existence of many intermediate states at low temperatures stabilized by the force. A unified response
of pulling and compressing force has been obtained in the constant-distance ensemble. We show the signature of a cross-over length which increases linearly with the chain length. Below this cross-over length, the critical force of unfolding decreases with temperature, while above, it increases with temperature. For stiff chains, we report for the first time a ‘saw-tooth’ like behavior in the force-extension curves which has been seen earlier in the case of protein unfolding.

For More Information: Dr. Iwan Jensen Phone: +61 3 8344 5214