文献类型： 外文期刊

作者： Yang Qiao ¹ ; Zhang Xiao-Ling ³ ; Zhang Lei ² ; Dai Jun ² ; Zhang Jun-Xiang ² ; Jiao Bing-Hua ¹ ;

作者机构： 1.Second Mil Med Univ, Dept Biochem & Mol Biol, Shanghai 200433, Peoples R China

2.Wuhan Univ, Coll Life Sci, State Key Lab Virol, Wuhan 430072, Peoples R China

3.Chinese Acad Fishery Sci, E China Sea Fisheries Res Inst, Shanghai 200090, Peoples R China

关键词： Deinococcus radiodurans;carotenoids;radioresistance;free radicals

期刊名称：PROGRESS IN BIOCHEMISTRY AND BIOPHYSICS （ 影响因子：0.351； 五年影响因子：0.272 ）

ISSN： 1000-3282

年卷期： 2009 年 36 卷 6 期

页码：

收录情况： SCI

摘要： To investigate the biosynthetic genes and the biological functions of carotenoids on the radioresistant mechanisms of the extremely radioresistant bacterium, Deinococcus radiodurans, the carotenoids of this bacterium were extracted with cold methanol and acetone, then were isolated and analyzed by LC-MS technique. Two colorless mutants knocking out of the phytoene synthase (crtB) and phytoene desaturase (crtI) genes were constructed by PCR and in vivo homologous recombination. The successful construction was confirmed by phenotype observation and carotenoids analysis by high performance liquid chromatography (HPLC). Comparative analysis of the sensitivities among the two colorless mutants and wild RI showed that the two colorless mutants were more sensitive to ionizing radiation (IR) and ultraviolet (UV), indicating that the deletion of crtB and crtI genes made the mutants unable to biosynthesize the crucial intermediate lycopene and series of downstreaming carotenoids. The scavenging abilities of the two carotenoids were measured using the ultraviolet induction of bacteriophage lambda (UIB) system and electron spin resonance (ESR) spin trapping technique in vivo and in vitro, respectively. The results showed that the main two carotenoids exhibited significant antioxidant capacities to superoxide anion (O-2(radical anion)) and hydroxyl radicals (center dot OH) which were two main types of free radicals produced during IR. This study has provided for the first time a new and direct evidence to explore the biosynthesis genes of carotenoids and their biological functions for the radioresistant mechanisms of D. radiodurans.