Escherichia coli phage-shock protein A (PspA) binds to membrane phospholipids and repairs proton leakage of the damaged membranes
Escherichia coli phage-shock protein A (PspA) binds to membrane phospholipids and repairs proton leakage of the damaged membranes
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DOI：
10.1111/j.1365-2958.2007.05893.x
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发表时间：
2007-10-01
影响因子：
3.6
通讯作者：
Yoshida, Masasuke
中科院分区：
文献类型：
--
作者：
Kobayashi, Ryuji;Suzuki, Toshiharu;Yoshida, Masasuke
大肠杆菌噬菌体休克蛋白A（PspA）是一种分子量为25.3 kDa的外周膜蛋白，在膜应激条件下被诱导，并被认为有助于维持膜电位。在这里，我们报告说，纯化的PspA，存在作为一个大的油，是真正能够抑制质子泄漏的膜。这在由缺乏PspA的E.大肠杆菌突变体，并为膜囊泡损伤乙醇和Triton X-100制备的突变体和野生型细胞。PspA还抑制由E.大肠杆菌总脂质。此外，我们发现PspA优先结合到含有磷脂酰丝氨酸和磷脂酰甘油的脂质体。对于通过脲变性的PspA的重折叠制备的单体PspA，没有观察到所有这些效果。这些结果表明，PspA的寡聚体与膜磷脂结合并抑制质子泄漏。
Escherichia coli phage-shock protein A (PspA), a 25.3 kDa peripheral membrane protein, is induced under the membrane stress conditions and is assumed to help maintain membrane potential. Here, we report that purified PspA, existing as a large oilgomer, is really able to suppress proton leakage of the membranes. This was demonstrated for membrane vesicles prepared from the PspA-lacking E. coli mutants, and for membrane vesicles damaged by ethanol and Triton X-100 prepared from the mutant and the wild-type cells. PspA also suppressed proton leakage of damaged liposomes made from E. coli total lipids. Furthermore, we found that PspA bound preferentially to liposomes containing phosphatidylserine and phosphatidylglycerol. All these effects were not observed for monomer PspA that was prepared by refolding of urea-denatured PspA. These results indicate that oligomers of PspA bind to membrane phospholipids and suppress proton leakage.