辣椒生育酚环化酶(TC)基因克隆和生物信息学分析

Cloning and Bioinformatics Analysis of Tocopherol Cyclase(TC) Gene in Capsicum annuum

维生素E包括生育酚和生育三稀酚,是一种脂溶性的抗氧化物质,同时也是一种重要的营养物质。在生育酚合成途径中,生育酚环化酶(tocopherol cyclase gene, TC)以2-甲基-6-植基-苯醌(2-methyl-6-phytobenzoquinone, MPBQ)和2,3-二甲基-6-植基-1,4-苯醌(2,3-dimethyl-6-phytogenic-1-4-benzoquinone, DMPBQ)为底物,分别生成易被人体吸收的α-生育酚和γ-生育酚,如果TC失活,会造成底物的积累以及生育酚的缺乏,因此TC是维生素E生物合成途径中下游的关键酶之一。本实验从贵州商业辣椒--黔椒4号中采用RACE方法克隆出TC基因全长,并利用生物信息学方法对该基因相关的理化性质、氨基酸保守结构区域、氨基酸同源性、进化树构建、二级结构等进行了详细的分析,为今后利用基因工程研究TC对辣椒维生素E含量及营养附加值的影响提供重要理论基础。

Vitamin E, including tocopherol and reproductive triethylphenol, is a kind of lipid soluble antioxidant and an important nutrient substance as well. In the biosynthesis pathway of tocopherol, the tocopherol cyclase(TC)uses the 2-methyl-6-phyto-benzoquinone(MPBQ) and 2,3-dimethyl-6-phytogenic-1-1-4-benzoquinone(DMPBQ) as the substrates, and convert them into α-tocopherol and γ-tocopherol respectively which could be absorbed easily by the human body. If TC is inactivated, it will lead to the accumulation of substrate and the deficiency of tocopherol, so TC is one of the key enzymes in the middle and lower reaches of vitamin E biosynthesis pathway. In this experiment, the complete cDNA of TC was cloned by RACE method from Guizhou commercial pepper(No.4, Qian pepper). The bioinformatics methods were used to analyze the related physical and chemical properties,amino acid conserved structure area, amino acid homology, evolution tree construction, and secondary structure of the gene in detail. Dates above could provide an important theoretical basis for the effect of TC on vitamin E content and nutritional value in Capsicum by using genetic engineering method.