Abstract
We have used an optical trap to measure or exert a force on single actin filaments via the attachment of polystyrene beads which were coated with NEM-modified HMM. In the simplest experiment, beads were attached to rhodamine phalloidin labelled actin filaments and observed to move on an HMM coated surface in the presence of ATP. Moving beads were steered into the vicinity of the trap using a PZT operated microscope stage. The minimum force needed to stop a moving bead was measured by lowering the trap strength until the bead resumed movement. By aligning the optical trap with the centre of a quadrant detector placed in an image plane of the microscope, it was possible to measure the force exerted on a filament by measuring the displacement of the bead position from the centre of the trap. In each of these experiments, the trap was calibrated by applying a Stokes force to a bead in free solution. The characteristics of the trap were studied, and the displacement of the bead from the centre of the trap was shown to be directly proportional to the applied force over a large part of the total range of the trap. The compliance of the trap could be substantially reduced by the use of feedback control to deflect the laser beam via an acousto-optic modulator. The advantages and limitations of this technique will be discussed.
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
Preview
Unable to display preview. Download preview PDF.
References
Ashkin, A., Dziedzic, J.M., Bjorkholm, J.E. & Chu, S. Optics Lett. 11, 288–290.
Ishijima A., Doi, T., Sakurada, K. & Yanagida, T. Nature 352, 301–306 (1991).
Block, S.M., Goldstein, L.S.B. & Schnapp, B.J. Nature 348, 348–352 (1990).
Kron, S.J. & Spudich, J.A. Proc. Natl. Acad. Sci. USA 83, 6272–6276 (1981).
Uyeda, T.Q.P., Kron, S.J. & Spudich, J.A. J. Mol. Biol. 214, 669–710 (1990).
Author information
Authors and Affiliations
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 1993 Springer Science+Business Media New York
About this chapter
Cite this chapter
Simmonst, R.M., Finer, J.T., Warrick, H.M., Kralik, B., Chu, S., Spudich, J.A. (1993). Force on Single Actin Filaments in a Motility Assay Measured with an Optical Trap. In: Sugi, H., Pollack, G.H. (eds) Mechanism of Myofilament Sliding in Muscle Contraction. Advances in Experimental Medicine and Biology, vol 332. Springer, Boston, MA. https://doi.org/10.1007/978-1-4615-2872-2_32
Download citation
DOI: https://doi.org/10.1007/978-1-4615-2872-2_32
Publisher Name: Springer, Boston, MA
Print ISBN: 978-1-4613-6245-6
Online ISBN: 978-1-4615-2872-2
eBook Packages: Springer Book Archive