Protective action of bacterial melanin against spectrums by a sensitive plasmid-based DNA damage in full UV noncellular system
Protective action of bacterial melanin against spectrums by a sensitive plasmid-based DNA damage in full UV noncellular system
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DOI：
10.1016/j.jprot.2007.12.013
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发表时间：
2008-04-24
影响因子：
--
通讯作者：
Chen, Xiang-Dong
中科院分区：
文献类型：
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作者：
Geng, Jing;Yu, Sheng-Bing;Chen, Xiang-Dong
本研究的目的是引入一种简单且灵敏的基于质粒的非细胞系统，以评估细菌黑色素对紫外线 (UV) 辐射 DNA 损伤的光保护作用。通过一系列体外测定，使用质粒 DNA 来评估黑色素在不同范围的紫外线中的作用。荧光测量表明，黑色素可以有效清除溶液中UVA照射产生的活性氧（ROS），且清除能力与色素浓度成正比。 UVB照射下黑色素对质粒DNA的保护作用通过受保护DNA的转化效率得到证实，该效率比非黑色素保护DNA的转化效率至少高10倍。 UVC 照射后，通过激光诱导荧光毛细管电泳对链断裂的 DNA 损伤进行定量。超螺旋质粒的百分比从80%减少到没有黑色素保护的5%以下。相比之下，在相同辐射条件下，在黑色素存在的情况下，超螺旋DNA的百分比仅下降至约40%。所有这些结果都表明，细菌黑色素确实可以保护 DNA 在整个紫外线照射过程中免受损坏。该系统避免了细胞DNA修复机制和细胞内物质的潜在干扰，可以提供一种灵敏的体外方法来评估黑色素和其他不同来源的光保护化合物的功能。 (c) 2008 Elsevier B.V. 保留所有权利。
The purpose of this study was to introduce a simple and sensitive plasmid-based noncellular system to evaluate the photoprotection of bacterial melanin on DNA damage against ultraviolet (UV) radiation. Plasmid DNA was used to assess the role of melanin in different ranges of UV using a series of in vitro assays. Fluorometric measurements suggested that melanin could efficiently scavenge reactive oxygen species (ROS) generated by UVA irradiation in solution, and the scavenging capability was proportional to the pigment concentration. The protective effect of melanin on plasmid DNA under UVB irradiation was confirmed by the transformation efficiency of the protected DNA, which was at least 10-fold higher than that of the non melanin protected DNA. After the UVC irradiation, the DNA damage of strand breaks was quantified by laser-induced fluorescence capillary electrophoresis. The percentage of supercoiled plasmid was reduced from 80% to less than 5% without melanin protection. In contrast, the percentage of supercoiled DNA only decreased to about 40% in the presence of melanin under the same radiation conditions. All these results demonstrated that bacterial melanin did protect DNA from being damaged throughout full UV irradiation. This system, avoiding the potential interference by cellular DNA repair machinery and intracellular substances, may provide a sensitive in vitro means to evaluate the functions of melanin and other photoprotective compounds from different sources. (c) 2008 Elsevier B.V. All rights reserved.