@article {Kuo232, author = {Kuo, SC and Sheetz, MP}, title = {Force of single kinesin molecules measured with optical tweezers}, volume = {260}, number = {5105}, pages = {232--234}, year = {1993}, doi = {10.1126/science.8469975}, publisher = {American Association for the Advancement of Science}, abstract = {Isometric forces generated by single molecules of the mechanochemical enzyme kinesin were measured with a laser-induced, single-beam optical gradient trap, also known as optical tweezers. For the microspheres used in this study, the optical tweezers was spring-like for a radius of 100 nanometers and had a maximum force region at a radius of approximately 150 nanometers. With the use of biotinylated microtubules and special streptavidin-coated latex microspheres as handles, microtubule translocation by single squid kinesin molecules was reversibly stalled. The stalled microtubules escaped optical trapping forces of 1.9 +/- 0.4 piconewtons. The ability to measure force parameters of single macromolecules now allows direct testing of molecular models for contractility.}, issn = {0036-8075}, URL = {https://science.sciencemag.org/content/260/5105/232}, eprint = {https://science.sciencemag.org/content/260/5105/232.full.pdf}, journal = {Science} }