Europhys. Lett.
Volume 69, Number 4, February 2005
Page(s) 643 - 649
Section Interdisciplinary physics and related areas of science and technology
Published online 19 January 2005
Europhys. Lett., 69 (4), pp. 643-649 (2005)
DOI: 10.1209/epl/i2004-10390-3

Work probability distribution in single-molecule experiments

A. Imparato and L. Peliti

Dipartimento di Scienze Fisiche and Unità INFM, Università "Federico II" Complesso Universitario di Monte S. Angelo, I-80126 Napoli, Italy

received 7 October 2004; accepted in final form 13 December 2004
published online 19 January 2005

We derive and solve a differential equation satisfied by the probability distribution of the work done on a single biomolecule in a mechanical unzipping experiment. The unzipping is described as a thermally activated escape process in an energy landscape. The Jarzynski equality is recovered as an identity, independent of the pulling protocol. This approach allows one to easily evaluate, by numerical integration, the work distribution, once a few parameters of the energy landscape are known.

87.14.Gg - DNA, RNA.
82.37.-j - Single molecule kinetics.
82.37.Rs - Single molecule manipulation of proteins and other biological molecules.

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