Journal
BIOPHYSICAL JOURNAL
Volume 94, Issue 6, Pages 2160-2169Publisher
BIOPHYSICAL SOC
DOI: 10.1529/biophysj.107.119396
Keywords
-
Categories
Funding
- MRC [G0300412] Funding Source: UKRI
- Medical Research Council [G0300412] Funding Source: researchfish
- Medical Research Council [G0300412, G0300412(69192)] Funding Source: Medline
Ask authors/readers for more resources
The force-extension curve of single myosin subfragment-1 molecules, interacting in the rigor state with an actin filament, has been investigated at low [ATP] by applying a slow triangle-wave movement to the optical traps holding a bead-actin-bead dumbbell. In combination with a measurement of the overall stiffness of the dumbbell, this allowed characterization of the three extensible elements, the actin-bead links and the myosin. Simultaneously, another method, based on an analysis of bead position covariance, gave satisfactory agreement. The mean covariance-based estimate for the myosin stiffness was 1.79 pN/nm (SD = 0.7 pN/nm; SE = 0.06 pN/nm (n = 166 myosin molecules)), consistent with a recent report (1.7 pN/nm) from rabbit muscle fibers. In the triangle-wave protocol, the motion of the trapped beads during interactions was linear within experimental error over the physiological range of force applied to myosin (+/- 10 pN), consistent with a Hookean model; any nonlinear terms could not be characterized. Bound states subjected to forces that resisted the working stroke (i.e., positive forces) detached at a significantly lower force than when subjected to negative forces, which is indicative of a strain-dependent dissociation rate.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available