Probing the mechanical folding kinetics of TAR RNA by hopping, force-jump, and force-ramp methods.

ABSTRACT: Mechanical unfolding and refolding of single RNA molecules have previously been observed in optical traps as sudden changes in molecular extension. Two methods have been traditionally used: "force-ramp", with the applied force continuously changing, and "hopping". In hopping experiments the force is held constant and the molecule jumps spontaneously between two different states. Unfolding/refolding rates are measured directly, but only over a very narrow range of forces. We have now developed a force-jump method to measure the unfolding and refolding rates independently over a wider range of forces. In this method, the applied force is rapidly stepped to a new value and either the unfolding or refolding event is monitored through changes in the molecular extension. The force-jump technique

SUBMITTER: Li PT 

PROVIDER: S-EPMC1367024 | biostudies-literature | 2006 Jan

REPOSITORIES: biostudies-literature