Weak and strong states of kinesin and nod
Weak and strong states of kinesin and nod
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DOI：
10.1006/jmbi.1996.0147
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发表时间：
1996-03-22
影响因子：
5.6
通讯作者：
Cross, RA
中科院分区：
文献类型：
--
作者：
Crevel, IMTC;Lockhart, A;Cross, RA
驱动蛋白超家族分子马达通过与ATP周转偶联的构象变化循环沿微管（MT）沿着行进。为了探索偶联机制，我们滴定了两个超家族成员MT正末端定向驱动蛋白和MT负末端定向非红葡萄酒分离（ncd）的各种核苷酸对MT结合的影响。对于两种马达，由腺苷三磷酸双磷酸酶诱导的无核苷酸状态是最强的结合（K-d（kin）类似于0.003 μ M，K-d（ncd）类似于0.24 μ M），而ADP状态是最弱的结合（K-d（kin）类似于11.32 μ M，K-d（ncd）类似于12.02 μ M）。在ATP中，马达ADP状态占主导地位，因此结合是ADP样的，但在缓慢水解的类似物腺苷5 ′-O-（3-硫代三磷酸）存在下，存在向更紧密结合的转变（K-d（kin）类似于4.23 μ M，K-d（ncd）类似于2.34 μ M），与紧密结合马达ATP样状态被富集一致。在存在不可水解的类似物β，γ-亚氨基腺苷5 '-三磷酸的情况下，结合仍然更紧密（K-d（kin）类似于
Kinesin superfamily molecular motors step along microtubules (MTs) via a cycle of conformational changes which is coupled to ATP turnover. To probe the coupling mechanism, we titrated the effects of various nucleotides on MT binding by two superfamily members; MT plus-end-directed kinesin and MT minus-end-directed non claret disjunctional (ncd). For both motors, the nucleotide-free state induced by apyrase was the strongest binding (K-d(kin) similar to 0.003 mu M, K-d(ncd) similar to 0.24 mu M), whilst the ADP state was the weakest binding (K-d(kin) similar to 11.32 mu M, K-d(ncd) similar to 12.02 mu M) In ATP, the motor.ADP state dominates and the binding is accordingly ADP-like, but in the presence of the slowly hydrolysed analogue adenosine 5'-O-(3-thiotriphosphate) there is a shift towards tighter binding (K-d(kin) similar to 4.23 mu M, K-d(ncd) similar to 2.34 mu M), consistent with a tight-binding motor.ATP-like state being enriched. In the presence of non-hydrolysable analogue beta,gamma-imidoadenosine 5'-triphosphate the binding is still tighter (K-d(kin) similar to