Color discrimination in halobacteria: spectroscopic characterization of a second sensory receptor covering the blue-green region of the spectrum.
Color discrimination in halobacteria: spectroscopic characterization of a second sensory receptor covering the blue-green region of the spectrum.
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盐细菌中的颜色辨别：覆盖光谱蓝绿色区域的第二感觉受体的光谱表征。
DOI：
10.1073/pnas.83.19.7272
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发表时间：
1986
影响因子：
11.1
通讯作者：
Stoeckenius,W
中科院分区：
文献类型：
--
作者：
Wolff,EK;Bogomolni,RA;Scherrer,P;Hess,B;Stoeckenius,W
盐生盐杆菌被绿色和红色光吸引，而被蓝-绿色和较短波长的光排斥。细胞膜中的一种光致变色的视紫红质样蛋白质，感觉视紫红质sR 587，已被鉴定为长波长和近UV刺激的受体。蓝光的排斥作用的作用光谱与sR 587及其光循环中间体S373的吸收光谱之间的差异强烈表明光谱的蓝色区域存在额外的感光体。在完整细胞和细胞膜中的瞬时光诱导的吸光度变化显示，除了sR 587之外，存在第二光敏色素，其在480 nm附近具有最大吸收。它经历一个循环的光反应，半衰期为150毫秒。在360 nm附近有一个最大吸收的中间态已被解决。新色素的光谱特性与假定的蓝光排斥效应的感光体的功能一致。当视网膜合成受阻时，趋光反应和两种色素都不存在;两者都可以通过添加视网膜来恢复。这些结果证实并扩展了Takahashi等人[Takahashi，T.，富冈，H.，卡莫，N. & Kobatake，Y. 04 The Dog of the Woman（1985）Lett. 28，161-164]。古细菌H.因此，盐藻使用两种不同的机制进行颜色辨别;它使用两种具有不同光谱灵敏度的视紫红质样受体，以及这些受体中至少一种的光致变色性来区分覆盖可见光和近紫外光谱的三个区域。
Halobacterium halobium is attracted by green and red light and repelled by blue-green and shorter wavelength light. a photochromic, rhodopsin-like protein in the cell membrane, sensory rhodopsin sR587, has been identified as the receptor for the long-wavelength and near-UV stimuli. Discrepancies between the action spectrum for the repellent effect of blue light and the absorption spectrum of sR587 and its photocycle intermediate S373 strongly suggest the existence of an additional photoreceptor for the blue region of the spectrum. Transient light-induced absorbance changes in intact cells and cell membranes show, in addition to sR587, the presence of a second photoactive pigment with maximal absorption near 480 nm. It undergoes a cyclic photoreaction with a half-time of 150 msec. One intermediate state with maximal absorption near 360 nm has been resolved. The spectral properties of the new pigment are consistent with a function as the postulated photoreceptor for the repellent effect of blue light. The phototactic reactions and both pigments are absent when retinal synthesis is blocked; both can be restored by the addition of retinal. These results confirm and extend similar observations by Takahashi et al. [Takahashi, T., Tomioka, H., Kamo, N. & Kobatake, Y. (1985) FEMS Microbiol. Lett. 28, 161-164]. The archaeobacterium H. halobium thus uses two different mechanisms for color discrimination; it uses two rhodopsin-like receptors with different spectral sensitivities and also the photochromicity of at least one of these receptors to distinguish between three regions covering the visible and near-UV spectrum.