刺梨半乳糖内酯脱氢酶的序列特征和部分反应特性  

Sequence Characteristics and Some Enzymatic Reaction Properties of L-Galactono-1,4-Lactone Dehydrogenase from Rosa roxburghii Tratt

作　　者：安华明[1] 黄伟[1] 樊卫国[1] 刘庆林[1] 陈力耕[2] 

机构地区：[1]贵州大学喀斯特山地果树资源研究所,贵阳550025 [2]浙江大学园艺系,杭州310029

出　　处：《西南大学学报（自然科学版）》2008年第12期97-101,共5页Journal of Southwest University(Natural Science Edition)

基　　金：国家自然科学基金资助项目(30660114);贵州省自然科学基金资助项目(20062038);贵州省教育厅自然科学基金资助项目;贵州省优秀青年科技人才培养计划资助项目;贵州大学人才基金资助项目

摘　　要：分析和研究了从刺梨中克隆的维生素C合成关键酶半乳糖内酯脱氢酶的氨基酸序列特征及其基本生化反应特性.结果表明,该基因含有一段线粒体靶信号肽序列、2个跨膜区、一个典型的FAD结合域以及1个天冬酰胺糖基化位点、8个蛋白激酶C磷酸化位点、11个酪蛋白激酶2磷酸化位点、2个酪氨酸激酶磷酸化位点和4个N端十四(烷)酰化位点等潜在功能性或翻译后修饰位点.丫啶黄素显著抑制GalLDH活性,二价金属盐CuSO4和ZnSO4有部分抑制作用,而石蒜碱几乎没有作用.The sequence of L-galactono-1,4-1actone dehydrogenase （GalLDH）, a key enzyme in plant aseorbic acid （AsA） biosynthesis, from R. roxburghii Tratt was analyzed and its biochemical properties were studied. The results showed that the G-alLDH amino acid sequence included a putative cleavage site of the mitochondrial targeting peptide, a typical FAD-binding region, two trans-membrane regions, and many post-translational modification sites, including one ASN glycosylation site, eight PKC phospho sites, eleven CK2 phospho sites, two TYR phospho sites and four MYRISTYL sites. Furthermore, Acriflavine, a kind of flavoenzyme inhibitor, significantly inhibited the enzyme activity and bivalent metal salts （CuSO4 or ZnSO4） showed partly inhibiting effect, but lycorine, which is deemed to be an AsA biosynthesis inhibitor, had hardly any effect on GalLDH activity.

关 键 词：刺梨 半乳糖内酯脱氢酶 维生素C 序列特征 生化特性 

分 类 号：Q949.751.8[生物学—植物学] Q554.9