CDNA CLONING AND EXPRESSION OF POTATO POLYPHENOL OXIDASE
CDNA CLONING AND EXPRESSION OF POTATO POLYPHENOL OXIDASE
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DOI：
10.1007/bf00039618
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发表时间：
1993-01-01
影响因子：
5.1
通讯作者：
STEFFENS, JC
中科院分区：
文献类型：
--
作者：
HUNT, MD;EANNETTA, NT;STEFFENS, JC
植物的多酚氧化酶（PPO）是铜金属蛋白，其催化单酚和邻二酚氧化成邻二醌。尽管多酚氧化酶被认为是导致许多水果和蔬菜作物有害褐变的主要原因，并且被认为参与了植物与害虫的相互作用，但缺乏这些作用的直接证据。我们报道了从马铃薯叶中克隆两个 PPO cDNA。这些 cDNA 在 DNA 和推导的氨基酸水平上分别表现出 97% 和 98% 的序列相似性。两种 cDNA 的推定铜结合区域与哺乳动物、细菌和脉孢菌酪氨酸酶的铜结合区域非常相似。两种叶 PPO cDNA 似乎都编码多肽，这些多肽被加工成成熟分子量为 57000。在马铃薯叶、叶柄、根和花中，PPO 由约 57000 编码。 2 kb 转录本。叶片 PPO mRNA 受发育调节，仅在幼叶中可检测到。相比之下，免疫学可检测的 PPO 的蛋白质谱从顶节到第十一个叶节保持恒定。
Polyphenol oxidases (PPOs) of plants are copper metalloproteins which catalyze the oxidation of mono- and o-diphenols to o-diquinones. Although PPOs are believed to be primarily responsible for the deleterious browning of many fruit and vegetable crops and are thought to be involved in plant-pest interactions, direct evidence for these roles is lacking. We report the cloning of two PPO cDNAs from Solanum tuberosum leaves. These cDNAs exhibit 97% and 98% sequence similarity at the DNA and deduced amino acid levels, respectively. Putative copper-binding regions of both cDNAs are very similar to those of mammalian, bacterial and Neurospora tyrosinases. Both leaf PPO cDNAs appear to encode polypeptides which are processed to a mature molecular weight of 57000. In potato leaves, petioles, roots, and flowers, PPO is encoded by ca. 2 kb transcripts. Leaf PPO mRNA is developmentally regulated and only detectable in young foliage. In contrast, the protein profile of immunologically detectable PPO remains constant from the apical node through the eleventh leaf node.