Thermal activation of single kinesin molecules with temperature pulse microscopy.
Conventional kinesin is a processive motor protein that keeps "walking" along a microtubule using chemical energy released by ATP hydrolysis. We previously studied the effects of temperature between 15 degrees and 35 degrees C on the moving velocity, force, and processivity of single kinesin molecules using a bead assay [Kawaguchi and Ishiwata, 2000b: Biochem Biophys Res Commun 272:895-899]. However, we could not examine the effects of temperature higher than 35 degrees C because of the thermal damage to proteins. Here, using temperature pulse microscopy (TPM) [Kato et al., 1999: Proc Natl Acad Sci USA 96:9602-9606], we could examine the temperature dependence of the gliding velocity of single kinesin molecules interacting with a microtubule above 35 degrees C up to 50 degrees C (instantaneously, approximately 60 degrees C), where the velocity reached 3.68 microm/s, the highest ever reported. The Arrhenius plot showed no breaks between 15 degrees and 50 degrees C with a unique activation energy of about 50 kJ/mol, suggesting that the molecular mechanism of kinesin motility is common over a broad temperature range including physiological temperature.
Kawaguchi
K
K
Department of Physics, School of Science and Engineering, Waseda University, Tokyo, Japan.
Ishiwata
S
S
D000818:Animals; D001921:Brain / Q000201:enzymology*; D002417:Cattle; D006358:Hot Temperature; D016547:Kinesins / Q000378:metabolism*; D008853:Microscopy / Q000379:methods; D008870:Microtubules / Q000378:metabolism*
D016547:Kinesins