The first stage in biological signaling is based on changes in the functional state of a receptor protein triggered by interaction of the receptor with its ligand(s). The light-triggered nature of photoreceptors allows studies on the mechanism of such changes in receptor proteins using a wide range of biophysical methods and with superb time resolution. Here, we critically evaluate current understanding of proton and electron transfer in photosensory proteins and their involvement both in primary photochemistry and subsequent processes that lead to the formation of the signaling state. An insight emerging from multiple families of photoreceptors is that ultrafast primary photochemistry is followed by slower proton transfer steps that contribute to triggering large protein conformational changes during signaling state formation. We discuss themes and principles for light sensing shared by the six photoreceptor families: rhodopsins, phytochromes, photoactive yellow proteins, light-oxygen-voltage proteins, blue-light sensors using flavin, and cryptochromes.

中文翻译：

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感光体负责：新兴的光感测原理。

生物信号转导的第一阶段基于受体蛋白质的功能状态变化，该变化是由受体与其配体的相互作用触发的。光感受器的光触发性质允许使用广泛的生物物理方法和极好的时间分辨率来研究受体蛋白质的这种变化的机制。在这里，我们批判性地评估当前对光感蛋白中质子和电子转移的理解，以及它们在初级光化学和导致信号状态形成的后续过程中的参与。来自多个感光受体家族的见解是，超快的一级光化学反应后是较慢的质子转移步骤，这些步骤有助于在信号状态形成过程中触发大的蛋白质构象变化。