Stochastic study of the effect of ionic strength on noncovalent interactions in protein pores.
Stochastic study of the effect of ionic strength on noncovalent interactions in protein pores.
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DOI：
10.1529/biophysj.107.117598
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发表时间：
2008-02-15
影响因子：
3.4
通讯作者：
Guan, Xiyun
中科院分区：
文献类型：
--
作者：
Zhao, Qitao;Jayawardhana, Dilani A.;Guan, Xiyun
盐在细胞的生理活动中起着至关重要的作用。我们发现离子强度显著影响蛋白质通道中非共价相互作用的动力学，正如在各种分析物通过野生型和突变的α-溶血素蛋白的孔转移的随机研究中观察到的那样。随着离子强度的增加，静电相互作用的缔合速率常数加快，疏水和芳香族相互作用的缔合速率常数减小。在所研究的所有非共价相互作用中，都观察到解离速率常数显著降低，从而总体反应生成常数增加。结果表明，随着盐浓度的增加，蛋白质孔的流动电位降低，但对阳离子或阴离子的选择性降低。此外，结果还表明，盐对分析物与孔的结合速率的影响明显不同，这取决于发生在蛋白质通道中的非共价相互作用的性质。除了对分析物-蛋白质孔相互作用的性质提供新的见解外，观察到的蛋白质孔中非共价相互作用的盐依赖性提供了一种有用的手段来极大地提高纳米孔的灵敏度，这可能在随机传感中找到有用的应用。
Salt plays a critical role in the physiological activities of cells. We show that ionic strength significantly affects the kinetics of noncovalent interactions in protein channels, as observed in stochastic studies of the transfer of various analytes through pores of wild-type and mutant α-hemolysin proteins. As the ionic strength increased, the association rate constant of electrostatic interactions was accelerated, whereas those of both hydrophobic and aromatic interactions were retarded. Dramatic decreases in the dissociation rate constants, and thus increases in the overall reaction formation constants, were observed for all noncovalent interactions studied. The results suggest that with the increase of salt concentration, the streaming potentials for all the protein pores decrease, whereas the preferential selectivities of the pores for either cations or anions drop. Furthermore, results also show that the salt effect on the rate of association of analytes to a pore differs significantly depending on the nature of the noncovalent interactions occurring in the protein channel. In addition to providing new insights into the nature of analyte-protein pore interactions, the salt-dependence of noncovalent interactions in protein pores observed provides a useful means to greatly enhance the sensitivity of the nanopore, which may find useful application in stochastic sensing.
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DOI：
10.1073/pnas.0601769103
发表时间：
2006-08-01
影响因子：
11.1
作者：
Bauer, Wolfgang R.;Nadler, Walter
通讯作者：
Nadler, Walter
DOI：
10.1073/pnas.2531778100
发表时间：
2003-12-23
影响因子：
11.1
作者：
Gu, LQ;Cheley, S;Bayley, H
通讯作者：
Bayley, H
影响因子：
15
作者：
Jung, Yuni;Bayley, Hagan;Movileanu, Liviu
通讯作者：
Movileanu, Liviu
影响因子：
15
作者：
Kang, Xiao-feng;Cheley, Stephen;Bayley, Hagan
通讯作者：
Bayley, Hagan
影响因子：
46.9
作者：
Movileanu, L;Howorka, S;Bayley, H
通讯作者：
Bayley, H