Force spectroscopy of a single artificial biomolecule bond: The Kramers’ high-barrier limit holds close to the critical force

Abstract

We use a minimal system with a single micron-size bead trapped with optical tweezers to investigate the kinetics of escape under force. Surprisingly, the exponential decay of the off rate with the barrier energy is still valid close to the critical force. Hence, the high viscosity approximation derived by Kramers in the case of a high energy barrier holds even for an energy barrier close to the thermal energy. Several recent models describe a single biomolecule bond by a smooth single-barrier energy profile. When this approach is accurate enough, our result justifies the use of Kramers’ approximation in the high-force regime, close to the critical force of the system, as done in recent single biomolecule bond studies.

Thermal activation at moderate-to-high and high damping: Finite barrier effects and force spectroscopy

“…This was also obtained in Ref. 51. We have also discussed the role of γ Ḟ as the relevant parameter at high damping.…”

Micropipette force probe to quantify single-cell force generation: application to T-cell activation

“…The gray levels along this line were cross-correlated with the gray levels of a template line acquired at the beginning of each recording (a strategy already used by the authors; Laan et al. , 2008 ; Husson et al. , 2009 ).…”

Tilting and Squeezing: Phase Space Geometry of Hamiltonian Saddle-Node Bifurcation and its Influence on Chemical Reaction Dynamics

“…This leads to drastic changes in the geometry of phase space structures -NHIM and its invariant manifolds -which can then be used to account for corrections to Kramers' reaction rate as barrier height decreases 27 . Furthermore, quantifying rates of crossing low or vanishing barrier is significant for experimental study of single bond dynamics of molecules and control of micro and nano-electromechanical devices [27][28][29][30] . We would also like to point out that the questions addressed in this article are further motivated by the work of Borondo and coauthors [31][32][33] who noted the significance of a saddle-node bifurcation in the isomerization of LiCN/LiNC molecule.…”