A pore-forming protein with a metal-actuated switch.
A pore-forming protein with a metal-actuated switch.
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具有金属驱动开关的成孔蛋白。
DOI：
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发表时间：
1994
期刊：
影响因子：
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通讯作者：
H. Bayley
中科院分区：
文献类型：
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作者：
B. Walker;J. Kasianowicz;M. Krishnasastry;H. Bayley
葡萄球菌α-溶血素是一种成孔外毒素，是由金黄色葡萄球菌作为水溶性单体分泌的293个氨基酸的多肽。它在脂质双层中组装形成六聚体孔。以前的研究孔的形成已经建立了一个中央甘氨酸丰富的循环的参与。在这里，我们表明，当五个连续的组氨酸残基取代氨基酸130-134在环的中点，他们提供了一个开关，孔活性可以（i）关闭的二价锌离子的微摩尔浓度和（ii）打开与螯合剂EDTA。平面双层记录显示，Zn 2+和EDTA可以从双层的任一侧作用于开放通道，从而证明中央回路线的导电通路的一部分。我们的研究结果表明，基因工程孔形成蛋白可能成为金属离子传感器的有用组件。
Staphylococcal alpha-hemolysin, a pore-forming exotoxin, is a polypeptide of 293 amino acids that is secreted by Staphylococcus aureus as a water-soluble monomer. It assembles to form hexameric pores in lipid bilayers. Previous studies of pore formation have established the involvement of a central glycine-rich loop. Here, we show that when five consecutive histidine residues replace amino acids 130-134 at the midpoint of the loop, they provide a switch with which pore activity can be (i) turned off by micromolar concentrations of divalent zinc ions and (ii) turned back on with the chelating agent EDTA. Planar bilayer recordings show that Zn2+ and EDTA can act on open channels from either side of the bilayer and thus demonstrate that the central loop lines part of the conductive pathway. Our results suggest that genetically-engineered pore-forming proteins might make useful components of metal ion sensors.