Scaling in force spectroscopy of macromolecules.
We use molecular dynamics to determine the force needed to rupture a chain molecule being stretched at constant loading rate and temperature. When all energy bonds of the molecule are identical, we find that the force F depends on the pulling rate r and temperature T according to F approximately const- T(1/3)|ln (r/T)|(1/3). When a single weak bond is introduced, this result is modified to F approximately const - T(2/3|ln (r/T)(2/3)|. This scaling, which is model independent, can be used with experiment to quantitatively extract relevant microscopic parameters.
Dias
Cristiano L
CL
Physics Department, Rutherford Building, McGill University, Montréal, Québec,Canada.
Dubé
Martin
M
Oliveira
Fernando A
FA
Grant
Martin
M
D000818:Animals; D001703:Biophysics / Q000379:methods; D003198:Computer Simulation; D006801:Humans; D018625:Microscopy, Atomic Force / Q000379:methods*; D015233:Models, Statistical; D008962:Models, Theoretical; D013053:Spectrophotometry / Q000379:methods*; D013269:Stochastic Processes; D013696:Temperature; D013816:Thermodynamics