The mechanism regulating the activity of dynein, an oscillatory motor protein.

鞭毛运动的一个显著特征是摆动。鞭毛的振荡运动是基于动力蛋白的活性，动力蛋白是微管运动蛋白之一。在这项研究中，我旨在阐明鞭毛轴丝中动力蛋白活性的调节机制。我使用的是海胆精子鞭毛，这些鞭毛去膜、碎裂，然后用弹性蛋白酶处理。笼状三磷酸腺苷的闪光光解导致经弹性酶处理的轴丝滑动成两组双胞体，其中一组包含中心对。我研究了弯曲这些双重群中的一部分的影响，发现弯曲引起了两个特征变化。一个是两组双胞胎之间滑动速度的增加。另一个变化是滑动模式，也就是说，滑动发生在九个双打中的任何两个之间。这些结果表明，微管弯曲参与了动力蛋白活性的调节。在第二个实验中，利用单线微管与暴露在双线组的双线上的动力蛋白臂相互作用，研究了中心对对动力蛋白活性的影响。我发现，在高钙条件下，中心对的存在抑制了动力蛋白的滑动活动。在第三个实验中，测量了机械扰动对动力蛋白单臂振荡力的影响，发现振荡力随施加在双线或微管上的机械变化而变化。

A prominent feature of flagellar motility is an oscillation. Flagellar oscillatory movement is based on the activity of dynein, which is one of the microtubule motor proteins. In this study I aimed to elucidate the mechanism regulating the dynein activity in the flagellar axonemes. I used sea urchin sperm flagella, which were demembranated, fragmented and then treated with elastase. A flash photolysis of caged ATP induced sliding of the elastase-treated axonemes into two groups of doublets, one of them contained the central pair. I investigated an effect of bending a part of these doublet groups and found that the bending induced two characteristic changes. One was an increase in the velocity of sliding between the two groups of the doublets. Another change was a sliding pattern, that is, the sliding occurred between any two of the nine doublets. These results indicate that the microtubule bending is involved in the regulation of dynein activity. In the second experiment, an effect of the central pair on dynein activity was studied by using singlet microtubules, which interacted with exposed dynein arms on doublets of the doublet groups. I found that the presence of the central pair inhibited the sliding activity of dynein at high calcium conditions. In the third experiment, effects of mechanical perturbation on the oscillatory force of a single dynein arm was measured and the oscillatory force was reveled to be changed by the mechanical changes applied to the doublet or the microtubules.