Fliegmann J, Sandermann H
GSF-Forschungszentrum für Umwelt und Gesundheit, Institut für Biochemische Pflanzenpathologie, Oberschleissheim, Germany.
Plant Mol Biol. 1997 Aug;34(6):843-54. doi: 10.1023/a:1005872222490.
We have previously shown that intact plants and cultured plant cells can metabolize and detoxify formaldehyde through the action of a glutathione-dependent formaldehyde dehydrogenase (FDH), followed by C-1 metabolism of the initial metabolite (formic acid). The cloning and heterologous expression of a cDNA for the glutathione-dependent formaldehyde dehydrogenase from Zea mays L. is now described. The functional expression of the maize cDNA in Escherichia coli proved that the cloned enzyme catalyses the NAD(+)- and glutathione (GSH)-dependent oxidation of formaldehyde. The deduced amino acid sequence of 41 kDa was on average 65% identical with class III alcohol dehydrogenase from animals and less than 60% identical with conventional plant alcohol dehydrogenases (ADH) utilizing ethanol. Genomic analysis suggested the existence of a single gene for this cDNA. Phylogenetic analysis supports the convergent evolution of ethanol-consuming ADHs in animals and plants from formaldehyde-detoxifying ancestors. The high structural conservation of present-day glutathione-dependent FDH in microorganisms, plants and animals is consistent with a universal importance of these detoxifying enzymes.
我们之前已经表明，完整的植物和培养的植物细胞可以通过谷胱甘肽依赖性甲醛脱氢酶（FDH）的作用代谢并解毒甲醛，随后对初始代谢产物（甲酸）进行C-1代谢。本文描述了来自玉米（Zea mays L.）的谷胱甘肽依赖性甲醛脱氢酶cDNA的克隆和异源表达。玉米cDNA在大肠杆菌中的功能表达证明，克隆的酶催化NAD(+)和谷胱甘肽（GSH）依赖性的甲醛氧化。推导的41 kDa氨基酸序列与动物的III类醇脱氢酶平均有65%的同一性，与利用乙醇的传统植物醇脱氢酶（ADH）的同一性不到60%。基因组分析表明该cDNA存在单个基因。系统发育分析支持动物和植物中消耗乙醇的ADH从解毒甲醛的祖先趋同进化。当今微生物、植物和动物中谷胱甘肽依赖性FDH的高度结构保守性与这些解毒酶的普遍重要性相一致。
