RT Journal Article
SR Electronic
T1 Equilibrium Information from Nonequilibrium Measurements in an Experimental Test of Jarzynski's Equality
JF Science
JO Science
FD American Association for the Advancement of Science
SP 1832
OP 1835
DO 10.1126/science.1071152
VO 296
IS 5574
A1 Liphardt, Jan
A1 Dumont, Sophie
A1 Smith, Steven B.
A1 Tinoco, Ignacio
A1 Bustamante, Carlos
YR 2002
UL http://science.sciencemag.org/content/296/5574/1832.abstract
AB Recent advances in statistical mechanical theory can be used to solve a fundamental problem in experimental thermodynamics. In 1997, Jarzynski proved an equality relating the irreversible work to the equilibrium free energy difference, ΔG. This remarkable theoretical result states that it is possible to obtain equilibrium thermodynamic parameters from processes carried out arbitrarily far from equilibrium. We test Jarzynski's equality by mechanically stretching a single molecule of RNA reversibly and irreversibly between two conformations. Application of this equality to the irreversible work trajectories recovers the ΔG profile of the stretching process to withink B T/2 (half the thermal energy) of its best independent estimate, the mean work of reversible stretching. The implementation and test of Jarzynski's equality provides the first example of its use as a bridge between the statistical mechanics of equilibrium and nonequilibrium systems. This work also extends the thermodynamic analysis of single molecule manipulation data beyond the context of equilibrium experiments.