香蕉PPO基因的克隆及原核表达

Cloning and Prokaryotic Expression of PPO Gene in Banana

为进一步在蛋白水平上研究香蕉PPO功能及获得抗酶促褐变的香蕉新品种,通过PCR从巴西蕉中扩增出多酚氧化酶基因(PPO)全长序列,并进行进化树分析与SDS-PAGE电泳检测。结果显示:多酚氧化酶基因全长1 767bp,编码588个氨基酸,GenBank登录号为KF900300.1。与其他物种PPO基因的氨基酸序列有很高的结构相似性,并同时具有保守结构域CuA和CuB,香蕉PPO蛋白与菠萝亲缘关系最近。另外,成功构建原核表达载体pQE80L-MaPPO1,并转化E.coli M15,但未表达出目的蛋白,推测可能与MaPPO1中存在导肽有关。

To further explore banana PPO function in protein level and obtain banana varieties resistant to enzymatic browning. The polyphenol oxidase （PPO, GenBank accession No. KF900300. 1） gene was amplified from brazil banana by PCR, and the phylogeny analysis and SDS-PAGE electrophoresis were conducted. Results： The PPO DNA sequence was 1767 bp and encoded a protein of 588 amino acid residues. Sequence alignment showed that amino acid sequence of banana PPO protein had high identity to other species, and all contained conservative domains CuA and CuB. The phylogeny analysis showed that it had a most close phylogenetic relationship with Ananas comosus. In addition, the prokaryotic expression vector pQESOL-MaPPO1 was constructed and transformed to E. coli M15, but the purpose protein did not express, it was speculated that it may be associated with guide peptide of MaPPO1.