article · 14/08/2009
Protein Friction Limits Diffusive and Directed Movements of Kinesin Motors on Microtubules
Résumé
Friction limits the operation of macroscopic engines and is critical to the performance of micromechanical devices. We report measurements of friction in a biological nanomachine. Using optical tweezers, we characterized the frictional drag force of individual kinesin-8 motor proteins interacting with their microtubule tracks. At low speeds and with no energy source, the frictional drag was related to the diffusion coefficient by the Einstein relation. At higher speeds, the frictional drag force increased nonlinearly, consistent with the motor jumping 8 nanometers between adjacent tubulin dimers along the microtubule, and was asymmetric, reflecting the structural polarity of the microtubule. We argue that these frictional forces arise from breaking bonds between the motor domains and the microtubule, and they limit the speed and efficiency of kinesin.
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Bormuth, V., Varga, V., Howard, J., & Schaeffer, E. (2009). Protein Friction Limits Diffusive and Directed Movements of Kinesin Motors on Microtubules. Science, 325(5942). https://doi.org/10.1126/science.1174923@article{Bormuth2009_137,
author = {Bormuth, Volker and Varga, Vladimir and Howard, Jonathon and Schaeffer, Erik},
year = {2009},
month = {8},
title = {Protein Friction Limits Diffusive and Directed Movements of Kinesin Motors on Microtubules},
journal = {Science},
publisher = {AMER ASSOC ADVANCEMENT SCIENCE},
volume = {325},
number = {5942},
address = {1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA},
abstract = {Friction limits the operation of macroscopic engines and is critical to the performance of micromechanical devices. We report measurements of friction in a biological nanomachine. Using optical tweezers, we characterized the frictional drag force of individual kinesin-8 motor proteins interacting with their microtubule tracks. At low speeds and with no energy source, the frictional drag was related to the diffusion coefficient by the Einstein relation. At higher speeds, the frictional drag force increased nonlinearly, consistent with the motor jumping 8 nanometers between adjacent tubulin dimers along the microtubule, and was asymmetric, reflecting the structural polarity of the microtubule. We argue that these frictional forces arise from breaking bonds between the motor domains and the microtubule, and they limit the speed and efficiency of kinesin.},
url = {http://www.dx.doi.org/10.1126/science.1174923},
doi = {10.1126/science.1174923},
issn = {0036-8075},
}TY - JOUR
AU - Bormuth, Volker
AU - Varga, Vladimir
AU - Howard, Jonathon
AU - Schaeffer, Erik
PY - 2009
DA - 2009/08/14
TI - Protein Friction Limits Diffusive and Directed Movements of Kinesin Motors on Microtubules
JO - Science
VL - 325
IS - 5942
PB - AMER ASSOC ADVANCEMENT SCIENCE
SN - 0036-8075
AB - Friction limits the operation of macroscopic engines and is critical to the performance of micromechanical devices. We report measurements of friction in a biological nanomachine. Using optical tweezers, we characterized the frictional drag force of individual kinesin-8 motor proteins interacting with their microtubule tracks. At low speeds and with no energy source, the frictional drag was related to the diffusion coefficient by the Einstein relation. At higher speeds, the frictional drag force increased nonlinearly, consistent with the motor jumping 8 nanometers between adjacent tubulin dimers along the microtubule, and was asymmetric, reflecting the structural polarity of the microtubule. We argue that these frictional forces arise from breaking bonds between the motor domains and the microtubule, and they limit the speed and efficiency of kinesin.
DO - 10.1126/science.1174923
UR - http://www.dx.doi.org/10.1126/science.1174923
ER -