通过PCR方法克隆丰水梨PPO基因全长,并将其登录Genebank,登录号JQ861265。基因全长1782βbp,无内含子,编码的PPO属于亲水性蛋白质,无跨膜结构,含有593个氨基酸,分子量约为65.8βkDa,理论等电点为8.4。N端含有一段由47个氨基酸组成的转运肽。去除转运肽的成熟PPO分子量为60.8βkDa,理论等电点为6.69。PPO中含有两个铜离子结合区,主要位于PPO二级结构中的α-螺旋区域中。原核诱导目的蛋白在诱导3~6βh后积累量较大。诱导蛋白（PPO前体和成熟PPO）均能氧化儿茶素形成茶黄素。
：The polyphenol oxidase (PPO, GenBank accession No. JQ861265) genes were cloned by PCR from Pyrus Pyrifolia Nakai. The full length of PPO gene was 1β782βbp without introns, coding a precursor peptide. PPO precursor consists of 593 amino acids with a molecular weight of about 65.8βkDa. It has a theoretical PI of 8.4 and has a transit peptide consisting of 47 amino acids. The mature PPO without transit peptide consists of 547 amino acids with a molecular weight of about 60.8βkDa and a theoretical PI of 6.69. There are 2 Cu-binding domain in the α-helix of PPOs. The protein accumulation got a peak in 3-6 hours. The induced proteins (precursor PPO and mature PPO) can oxidize catechins into theaflavins in vitro.
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