Shpetner H S, Vallee R B
Cell Biology Group, Worcester Foundation for Experimental Biology, Shrewsbury, Massachusetts 01545.
Cell. 1989 Nov 3;59(3):421-32. doi: 10.1016/0092-8674(89)90027-5.
We report that calf brain microtubules prepared without nucleotide contain, in addition to kinesin and dynein, a polypeptide of 100 kd that could be dissociated by nucleotide. The protein was selectively extracted from microtubules using a combination of GTP and AMP-PNP. The extract contained microtubule-stimulated (6-fold) MgATPase activity that partitioned into two components upon further purification: the 100 kd polypeptide and a soluble activating fraction. The 100 kd protein induced microtubules to form hexagonally packed bundles containing periodic cross bridges spaced 13 nm apart. In the presence of ATP and the activating fraction, bundles fragmented, elongated, and exhibited other behavior indicative of sliding between microtubules. These findings indicate that the 100 kd protein is part of a novel mechanochemical enzyme, which we term "dynamin", that may mediate microtubule sliding in vivo.
我们报告称，在没有核苷酸的情况下制备的小牛脑微管，除了含有驱动蛋白和动力蛋白外，还含有一种100kd的多肽，该多肽可被核苷酸解离。使用GTP和AMP-PNP的组合从微管中选择性提取该蛋白质。提取物含有微管刺激的（6倍）MgATP酶活性，进一步纯化后可分为两个组分：100kd多肽和可溶性激活组分。100kd蛋白质诱导微管形成六边形排列的束，其中包含间隔13nm的周期性交叉桥。在ATP和激活组分存在的情况下，束会断裂、伸长，并表现出其他表明微管间滑动的行为。这些发现表明，100kd蛋白质是一种新型机械化学酶的一部分，我们将其称为“发动蛋白”，它可能在体内介导微管滑动。
