Photoactive retinal pigments in haloalkaliphilic bacteria.
Photoactive retinal pigments in haloalkaliphilic bacteria.
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DOI：
10.1099/00221287-132-8-2167
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发表时间：
1986-08
期刊：
影响因子：
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通讯作者：
D. Bivin;W. Stoeckenius
中科院分区：
文献类型：
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作者：
D. Bivin;W. Stoeckenius
光诱导的快速瞬态吸光度的变化进行了检测的时间分辨光谱在38的51 haloalkaliphilic菌株在肯尼亚和埃及的瓦迪Natrun碱性盐湖。它们表明存在两种视网膜色素，Pf和Ps，其经历循环光反应，半衰期分别为2 ms和500 ms。Pf在580 nm附近吸收最大，Ps在500 nm附近吸收最大。不同的颜料在其敏感性羟胺和洗涤剂漂白和Pf的光反应是强烈依赖于氯化物浓度。在38株含色素菌株中，29株同时具有Pf和Ps，9株仅具有Ps。尼古丁抑制视网膜的合成可阻断色素的形成，而加入视黄醛可使色素恢复。羟胺漂白的色素可与视黄醛或视黄醛类似物重组。它们与盐生盐杆菌视网膜色素的相似性强烈表明它们也是视紫红质样retinyledene蛋白。Pf在所有测试的性质上几乎与H.盐，并且可以在卤代亲碱物中起相同的作用。PS具有类似于感觉视紫红质的光循环动力学和远蓝移的长寿命光循环中间体，但其基态吸收最大值接近500 nm而不是587 nm。我们还没有发现一种细菌视紫红质类色素的haloalkaliphiles。
Light-induced fast transient absorbance changes were detected by time-resolved spectroscopy in 38 of 51 haloalkaliphilic isolates from alkaline salt lakes in Kenya and the Wadi Natrun in Egypt. They indicate the presence of two retinal pigments, Pf and Ps, which undergo cyclic photoreactions with half-times of 2 ms and 500 ms respectively. Pf absorbs maximally near 580 nm and Ps near 500 nm. The pigments differ in their sensitivity to hydroxylamine and detergent bleaching and the photoreactions of Pf are strongly dependent on chloride concentration. Of the 38 pigment-containing strains, 29 possess both Pf and Ps, 9 possess only Ps. Inhibition of retinal synthesis with nicotine blocks pigment formation and addition of retinal restores it. Hydroxylamine-bleached pigments can be reconstituted with retinal or retinal analogues. Their similarity to the retinal pigments of Halobacterium halobium strongly suggests that they are also rhodopsin-like retinyledene proteins. Pf in all properties tested is almost identical to halorhodopsin, the light-driven chloride pump of H. halobium, and may serve the same function in the haloalkaliphiles. Ps has photocycle kinetics similar to sensory rhodopsin and a far-blue-shifted long-lived photocycle intermediate, but its ground state absorption maximum is near 500 nm instead of 587 nm. We have not found a bacteriorhodopsin-like pigment in the haloalkaliphiles.