Timpe L C, Peller L
Program of Excellence in Molecular Biology, University of California, San Francisco 94143, USA.
Biophys J. 1995 Dec;69(6):2415-8. doi: 10.1016/S0006-3495(95)80111-6.
Rapid inactivation of Shaker K+ channels occurs when a domain in the amino terminal region of the channel protein blocks the pore. Some part of the sequence between the inactivating domain and the first transmembrane segment may form a flexible tether. We consider the possibility that the tether has no secondary structure, but is rather a polypeptide random coil. The local concentration of the tethered inactivation domain and the dependence of the inactivation rate on chain length can then be calculated by using the Jacobson-Stockmayer equation. A chain of 30-100 amino acids is consistent with the sensitivity of the inactivation rate to chain length mutations.
当通道蛋白氨基末端区域的一个结构域阻断孔道时，Shaker钾通道会迅速失活。失活结构域与第一个跨膜片段之间的部分序列可能形成一个柔性连接链。我们考虑了这种可能性，即连接链没有二级结构，而是一种多肽无规卷曲。然后可以使用雅各布森-斯托克迈耶方程计算连接的失活结构域的局部浓度以及失活速率对链长度的依赖性。30至100个氨基酸的链与失活速率对链长度突变的敏感性是一致的。
