THE CHEMISTRY OF DAYLIGHT VISION
THE CHEMISTRY OF DAYLIGHT VISION
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DOI：
10.1085/jgp.29.5.277
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发表时间：
1946-01-01
影响因子：
3.8
通讯作者：
BLISS, AF
中科院分区：
文献类型：
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作者：
BLISS, AF
虽然已经发表了几篇关于拥有大量视锥细胞的动物视网膜的光敏色素的报道，但唯一可以证实的研究是Wald发现的碘视蛋白，一种来自鸡眼睛的红色敏感色素。在其化学性质方面，如pH稳定性范围和极性有机溶剂的影响，碘视蛋白类似于视紫红质，但更不稳定。在用2%毛地黄皂苷提取之前，通过在pH 4.9的醋酸盐缓冲液中预硬化视网膜，实现了从黄色杂质中的部分纯化。通过在3/4饱和MgSO 4中用无患子苷提取未硬化的视网膜，由于视紫红质的污染减少了90%。碘视蛋白的漂白速率与能量呈一级线性关系。测定了碘伏的漂白效能谱。具有校准的滤色器，并且在560 μ处显示最大值。黄色绿色中有一个较低的蓝色平台。除了最大灵敏度波长540 μ外，光谱与人视锥细胞的灵敏度非常一致。先前关于青蛙视网膜的pH值和无机磷酸盐水平因光照而发生变化的报道无法得到证实。
While several reports of photosensitive pigments from the retinas of animals possessing large numbers of cone cells have been published, the only study which could be confirmed was Wald''s discovery of iodopsin, a red sensitive pigment from chicken eyes. In its chemical properties, such as range of pH stability and the effect of polar organic solvents, iodopsin resembles rhodopsin but is considerably more labile. A partial purification from yellow impurities has been effected by pre-hardening the retinas in pH 4.9 acetate buffer before extraction by 2% digitonin. Contamination due to rhodopsin was reduced 90% by extraction of unhardened retinas with sapinin in 3/4 saturated MgSC>4. The bleaching rate of iodopsin was found to be first order and linear with respect to energy. The bleaching effectiveness spectrum of iodopsin was detd. with calibrated color filters, and shows a maximum at 560 mu. in the yellow green with a lower plateau in the blue. The spectrum is in good agreement with the sensitivity of the human cones except for the wavelength of maximum sensitivity, 540 mu. Previous reports of changes in pH and inorganic phosphate level of frog retinas due to light could not be confirmed.