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Processivity of kinesin motility is enhanced on increasing temperature

View Article: PubMed Central - PubMed

ABSTRACT

Kinesin is a motor protein that processively moves step by step along a microtubule. To investigate the effects of temperature on run length, i.e., processivity of kinesin motility, we performed a single-molecular bead assay at temperature range of 20–40°C. An increase in the walking velocity of kinesin corresponded to the Arrhenius activation enthalpy of 48 kJ/mol, being consistent with the previous reports. Here, we found that the run length increased, that is, the kinesin processivity enhanced with increasing temperature. Then, we estimated the probability of detachment of kinesin from a microtubule per one 8-nm stepping event, and found that it diminishes from 0.014 to 0.006/step with increasing temperature from 20 to 40°C. And we noticed that prolonged incubation at 30, 35 and 40°C significantly slowed down the walking velocity, but further increased the run length and duration. Those results are interpreted according to the effect of temperature on the rate constants of some key kinetic steps in the ATPase cycle.

No MeSH data available.


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Arrhenius plot of walking velocity (ν) vs. absolute temperature (T). The activation enthalpy was estimated as 48 kJ/mol and 27 kJ/mol from the slope of the solid line and the dashed lines, respectively. Symbols are the same as in Figs. 2–4.
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f5-2_13: Arrhenius plot of walking velocity (ν) vs. absolute temperature (T). The activation enthalpy was estimated as 48 kJ/mol and 27 kJ/mol from the slope of the solid line and the dashed lines, respectively. Symbols are the same as in Figs. 2–4.

Mentions: The Arrhenius plot of the velocity obtained between 1 and 6 min of incubation was linear within the temperature range we examined (Fig. 5). The activation enthalpy was estimated to be 48 kJ/mol from the slope of the Arrhenius plot, being consistent with the previous data16,17. Here we found that, for the data obtained between 6 and 11 min of incubation, the linear relationship deviated from the straight line above around 30°C. These results imply that the protein functions are generally deteriorated by incubation at the elevated temperatures. The thermally deteriorated kinesin molecules may exhibit a slower rate of ATPase hydrolysis, and the walking velocity is therefore decreased. However, the detachment rate decreases to a larger extent, so that not only the duration but the run length as well is prolonged.


Processivity of kinesin motility is enhanced on increasing temperature
Arrhenius plot of walking velocity (ν) vs. absolute temperature (T). The activation enthalpy was estimated as 48 kJ/mol and 27 kJ/mol from the slope of the solid line and the dashed lines, respectively. Symbols are the same as in Figs. 2–4.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC5036643&req=5

f5-2_13: Arrhenius plot of walking velocity (ν) vs. absolute temperature (T). The activation enthalpy was estimated as 48 kJ/mol and 27 kJ/mol from the slope of the solid line and the dashed lines, respectively. Symbols are the same as in Figs. 2–4.
Mentions: The Arrhenius plot of the velocity obtained between 1 and 6 min of incubation was linear within the temperature range we examined (Fig. 5). The activation enthalpy was estimated to be 48 kJ/mol from the slope of the Arrhenius plot, being consistent with the previous data16,17. Here we found that, for the data obtained between 6 and 11 min of incubation, the linear relationship deviated from the straight line above around 30°C. These results imply that the protein functions are generally deteriorated by incubation at the elevated temperatures. The thermally deteriorated kinesin molecules may exhibit a slower rate of ATPase hydrolysis, and the walking velocity is therefore decreased. However, the detachment rate decreases to a larger extent, so that not only the duration but the run length as well is prolonged.

View Article: PubMed Central - PubMed

ABSTRACT

Kinesin is a motor protein that processively moves step by step along a microtubule. To investigate the effects of temperature on run length, i.e., processivity of kinesin motility, we performed a single-molecular bead assay at temperature range of 20–40°C. An increase in the walking velocity of kinesin corresponded to the Arrhenius activation enthalpy of 48 kJ/mol, being consistent with the previous reports. Here, we found that the run length increased, that is, the kinesin processivity enhanced with increasing temperature. Then, we estimated the probability of detachment of kinesin from a microtubule per one 8-nm stepping event, and found that it diminishes from 0.014 to 0.006/step with increasing temperature from 20 to 40°C. And we noticed that prolonged incubation at 30, 35 and 40°C significantly slowed down the walking velocity, but further increased the run length and duration. Those results are interpreted according to the effect of temperature on the rate constants of some key kinetic steps in the ATPase cycle.

No MeSH data available.


Related in: MedlinePlus