Temperature dependence of force, velocity, and processivity of single kinesin molecules
Temperature dependence of force, velocity, and processivity of single kinesin molecules
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DOI：
10.1006/bbrc.2000.2856
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发表时间：
2000-06-16
影响因子：
3.1
通讯作者：
Ishiwata, S
中科院分区：
文献类型：
--
作者：
Kawaguchi, K;Ishiwata, S
在光学显微镜下，我们用光学镊子检测了温度对单个激酶分子与微管相互作用的滑动速度、力和速度的影响。在15 ~ 35℃之间，随着Arrhenius活化能达到50 kJ/mol，滑动速度增加，这与微管依赖性atp酶活性的温度依赖性一致。此外，平均运行长度，即衡量动力蛋白的加工能力，随着温度的升高而增加。另一方面，产生的力与温度无关，为7.34 +/- 0.33 pN（平均+/- sd， n = 70）。滑翔速度几乎随力的增加而线性下降，与温度无关，这意味着机械化学能转换的效率在该温度范围内保持恒定。因此，我们认为力的产生是由于温度不敏感的核苷酸结合状态和/或微管复合物的构象变化，而滑动速度是由atp酶速率决定的。(C) 2000年学术出版社。
Using the bead assay in optical microscopy equipped with optical tweezers, we have examined the effect of temperature on the gliding velocity, force, and processivity of single kinesin molecules interacting with a microtubule between 15 and 35 degrees C. The gliding velocity increased with the Arrhenius activation energy of 50 kJ/mol, consistent with the temperature dependence of the microtubule-dependent ATPase activity. Also, the average run length, i.e., a measure of processivity of kinesin, increased on increasing temperature. On the other hand, the generated force was independent of temperature, 7.34 +/- 0.33 pN (average +/- S.D., n = 70). The gliding velocities decreased almost linearly with an increase in force irrespective of temperature, implying that the efficiency of mechanochemical energy conversion is maintained constant in this temperature range. Th us, we suggest that the force generation is attributable to the temperature-insensitive nucleotide-binding state(s) and/or conformational change(s) of kinesin-microtubule complex, whereas the gliding velocity is determined by the ATPase rate. (C) 2000 Academic Press.