Reconstitution of purified halorhodopsin.
Reconstitution of purified halorhodopsin.
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纯化的盐视紫红质的重构。
DOI：
10.1073/pnas.81.17.5408
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发表时间：
1984
影响因子：
11.1
通讯作者：
Stoeckenius,W
中科院分区：
文献类型：
--
作者：
Bogomolni,RA;Taylor,ME;Stoeckenius,W
含有盐视紫红质的 Asolectin 脂质囊泡在质子离子载体存在下表现出光诱导的酸化。这种效应被三苯基氯化锡（一种氯/羟基逆向转运蛋白）消除，并且在钾离子存在的情况下被缬氨霉素大大减弱，钾离子使膜电位崩溃。这表明盐视紫红质优先在脂质囊泡中从内向外定向，将氯化物泵入囊外室。 3 M NaCl 中的 asolectin 囊泡中的盐视紫红质的最大吸收位于 567 nm，光诱导 pH 变化的作用光谱紧随吸收光谱。用乙酸盐或硫酸盐替代氯化物会导致最大吸收偏移约等于 559 nm，并使泵失活。两种形式的不同光循环表明，80% 的分子的细胞外侧暴露于囊泡内部，并且与光谱转变相关的卤化物结合位点可从分子的细胞外侧接近。所提供的数据表明，纯化的色蛋白是盐杆菌中光驱动的氯泵。
Asolectin lipid vesicles containing halorhodopsin show light-induced acidification in the presence of proton ionophores. This effect is abolished by triphenyltin chloride, a chloride/hydroxyl antiporter, and is greatly diminished by valinomycin in the presence of potassium ions, which collapse the membrane potential. This indicates that halorhodopsin orients in the lipid vesicles preferentially inside out, pumping chloride into the extravesicular compartment. The absorption maximum of halorhodopsin in asolectin vesicles in 3 M NaCl is at 567 nm, and the action spectrum for the light-induced pH changes followed closely the absorption spectrum. Replacement of chloride by acetate or sulfate causes a shift in the absorption maximum to approximately equal to 559 nm and renders the pump inactive. The different photocycles of the two forms were used to show that 80% of the molecules have the extracellular side exposed to the vesicle interior and that the halide-binding site(s) associated with the spectral transition is accessible from the extracellular side of the molecule. The data presented demonstrate that the purified chromoprotein is the light-driven chloride pump in Halobacterium halobium.