Impact of distant charge reversals within a robust beta-barrel protein pore.
Impact of distant charge reversals within a robust beta-barrel protein pore.
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DOI：
10.1021/jp101311s
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发表时间：
2010-07-08
影响因子：
3.3
通讯作者：
Movileanu, Liviu
中科院分区：
文献类型：
--
作者：
Mohammad, Mohammad M.;Movileanu, Liviu
在所有的β-Barrel孔中，葡萄球菌α-溶血素(αHL)是一种已知的高分辨晶体结构的七聚体跨膜蛋白，在各种恶劣的实验条件下，它在平面脂双层中具有高度的稳定性。在这里，我们使用单通道电子记录和标准蛋白质工程来探索孔的β桶部分内部两个遥远的电荷反转的影响。电荷反转是用天冬氨酸取代赖氨酸。在靠近孔收缩的β桶的结构刚性区域内的电荷反转降低了孔的开态电流，但产生了安静的孔，表现出电流无波动的沟道行为。相反，在β桶的结构灵活的富含甘氨酸的转向中，跨入口处的电荷反转增加了开态电流，并以大幅度和频繁的电流波动的形式产生了孔的门控活动。值得注意的是，根据单通道和宏观电流测量的判断，两个距离较远的电荷反转的累积插入导致了对β桶的大范围永久封锁。这项工作的结果表明，这些遥远的电荷反转是能量耦合的，对离子输运、单位电导和孔洞的开态几率产生不同的影响。
Among all β-barrel pores, staphylococcal α-hemolysin (αHL), a heptameric transmembrane protein of known high-resolution crystal structure, features a high stability in planar lipid bilayers under a wide range of harsh experimental conditions. Here, we employed single-channel electrical recordings and standard protein engineering to explore the impact of two distant charge reversals within the interior of the β-barrel part of the pore. The charge reversals were replacements of lysines with aspartic acids. A charge reversal within the structurally stiff region of the β barrel near the pore constriction reduced the open-state current of the pore, but produced a quiet pore, showing current fluctuation-free channel behavior. In contrast, a charge reversal on the trans entrance, within the structurally flexible glycine-rich turn of the β barrel, increased the open-state current and produced gating activity of the pore in the form of large-amplitude and frequent current fluctuations. Remarkably, cumulative insertion of the two distant charge reversals resulted in a large-amplitude permanent blockade of the β barrel, as judged by both single-channel and macroscopic current measurements. The results from this work suggest that these distant charge reversals are energetically coupled, producing different impacts on the ionic transport, the unitary conductance and the open-state probability of the pore.
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影响因子：
15
作者：
Jung, Yuni;Bayley, Hagan;Movileanu, Liviu
通讯作者：
Movileanu, Liviu
DOI：
10.1093/protein/11.9.797
发表时间：
1998-09-01
期刊：
PROTEIN ENGINEERING
影响因子：
--
作者：
Liu, NZ;Delcour, AH
通讯作者：
Delcour, AH
影响因子：
3.4
作者：
Aksimentiev, A;Schulten, K
通讯作者：
Schulten, K
影响因子：
15
作者：
Howorka, S;Movileanu, L;Bayley, H
通讯作者：
Bayley, H
DOI：
10.1007/s00249-008-0309-9
发表时间：
2008-07-01
影响因子：
2
作者：
Mohammad, M. Mohammad;Movileanu, Liviu
通讯作者：
Movileanu, Liviu