Photoreactivity of amino acids: Tryptophan-induced photochemical events via reactive oxygen species generation
Photoreactivity of amino acids: Tryptophan-induced photochemical events via reactive oxygen species generation
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DOI：
10.2116/analsci.23.943
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发表时间：
2007-08-01
影响因子：
1.6
通讯作者：
Tsuda, Yoshiko
中科院分区：
文献类型：
--
作者：
Igarashi, Naoko;Onoue, Satomi;Tsuda, Yoshiko
色氨酸（Trp）是一种芳香族氨基酸，是肽/蛋白质的成分，也是血清素、犬尿氨酸衍生物和烟酰胺腺嘌呤二核苷酸的前体。已经有许多关于涉及含有Trp的肽/蛋白质的光化学反应的报道，这些肽/蛋白质显示出显著的光降解、二聚化和光电离。Trp的光化学性质尚未完全阐明，这将为含Trp的肽/蛋白质的处理提供新的见解。因此，我们一直试图评估的光化学性质的色氨酸，以及其他必需氨基酸，专注于它们的光敏性，光降解，以及它们的能力，以诱导脂质过氧化。在所有的必需氨基酸测试，色氨酸表现出最大水平的超氧阴离子产生下18小时的光照（30000勒克斯）。色氨酸的紫外光谱分析表明，UVA/B光的吸收能力，和曝光的色氨酸，在固体和溶液状态，UVA/B光导致显着的光降解（t（0.5）：18小时）和逐渐的颜色变化。此外，光照射色氨酸产生的脂质过氧化剂，光刺激的病原体，这可能与ROS的产生。
Tryptophan (Trp), an aromatic amino acid, is a constituent of peptides/proteins and is also a precursor of serotonin, kynurenine derivatives, and nicotinamide adenine dinucleotides. There have been a number of reports on photochemical reactions involving peptides/proteins which contain Trp that showed significant photodegradation, dimerization, and photoionization. The photochemical properties of Trp have not been fully elucidated, and this would provide novel insight into the handling of Trp-containing peptides/proteins. Consequently, we have been trying to evaluate the photochemical properties of Trp, as well as other essential amino acids, focusing on their photosensitivity, photodegradation, and their ability to induce lipid peroxidation. Among all the essential amino acids tested, Trp exhibited the maximal level of superoxide anion generation under 18 h of light exposure (30000 lux). UV spectral analysis of Trp suggested the absorbability of UVA/B light, and exposure of Trp, in both solid and solution states, to UVA/B light resulted in significant photodegradation (t(0.5): 18 h) and gradual color changes. In addition, photoirradiated Trp generated lipoperoxidant, a causative agent of photoirritation, and this might be associated with ROS generation.