BACTERIORHODOPSIN MONOMERS PUMP PROTONS
BACTERIORHODOPSIN MONOMERS PUMP PROTONS
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DOI：
10.1016/0014-5793(79)80552-9
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发表时间：
1979-01-01
期刊：
影响因子：
3.5
通讯作者：
HEYN, MP
中科院分区：
文献类型：
--
作者：
DENCHER, NA;HEYN, MP
盐生盐杆菌紫膜（PM）最显著的结构特征是细菌视紫红质（BR）在蛋白质三聚体的二维六边形晶格中的排列[2，3]。这就提出了一个问题，即这种不寻常的聚集状态是否是BR作为光驱动质子泵的功能所必需的。对于其他膜转运蛋白，通常认为只有特定的聚集体是功能性的。为了回答BR的这个问题，使用囊泡系统进行测量[4]，该系统非常适合比较单体和六方聚集BR的性质。仅通过将温度从低于脂质相变温度改变到高于脂质相变温度，BR的聚集状态可以以可逆的方式从六方聚集改变为单体[4]。所获得的结果表明，单体BR本身是能够泵质子，最有可能的效率没有显着不同的BR的六边形阵列。
The most striking structural feature of the purple membrane (PM) of Halobacterium halobium is the arrangement of bacteriorhodopsin (BR) in a twodimensional hexagonal lattice of protein trimers [2, 3]. This raises the question whether this unusual state of aggregation is required for the function of BR as a light-driven proton pump. For other membrane transport proteins it is generally believed that only specific aggregates are functional. In order to answer this question for BR measurements were performed with a vesicle system [4], which is ideally suited to compare the properties of monomeric and hexagonally aggregated BR. By merely changing the temperature from below the lipid phase transition temperature to above, the state of aggregation of BR can be altered in a reversible manner from hexagonally aggregated to monomeric [4]. The results obtained show that monomeric BR itself is able to pump protons, most probably with an efficiency not significantly different from that of BR in the hexagonal array.