Somssich I E, Wernert P, Kiedrowski S, Hahlbrock K
Max Planck Institut für Züchtungsforschung, Department of Biochemistry, D-50829 Köln, Germany.
Proc Natl Acad Sci U S A. 1996 Nov 26;93(24):14199-203. doi: 10.1073/pnas.93.24.14199.
We expressed a cDNA encoding the Arabidopsis thaliana defense-related protein ELI3-2 in Escherichia coli to determine its biochemical function. Based on a protein database search, this protein was recently predicted to be a mannitol dehydrogenase [Williamson, J. D., Stoop, J. M. H., Massel, M. O., Conkling, M. A. & Pharr, D. M. (1995) Proc. Natl. Acad. Sci. USA 92, 7148-7152]. Studies on the substrate specificity now revealed that ELI3-2 is an aromatic alcohol: NADP+ oxidoreductase (benzyl alcohol dehydrogenase). The enzyme showed a strong preference for various aromatic aldehydes as opposed to the corresponding alcohols. Highest substrate affinities were observed for 2-methoxybenzaldehyde, 3-methoxybenzaldehyde, salicylaldehyde, and benzaldehyde, in this order, whereas mannitol dehydrogenase activity could not be detected. These and previous results support the notion that ELI3-2 has an important role in resistance-related aromatic acid-derived metabolism.
我们在大肠杆菌中表达了编码拟南芥防御相关蛋白ELI3-2的cDNA,以确定其生化功能。基于蛋白质数据库搜索,该蛋白最近被预测为甘露醇脱氢酶[威廉姆森,J.D.,斯托普,J.M.H.,马塞尔,M.O.,康克林,M.A.和法尔,D.M.(1995年)《美国国家科学院院刊》92,7148 - 7152]。现在对底物特异性的研究表明,ELI3-2是一种芳香醇:NADP +氧化还原酶(苄醇脱氢酶)。与相应的醇相比,该酶对各种芳香醛表现出强烈的偏好。依次观察到对2-甲氧基苯甲醛、3-甲氧基苯甲醛、水杨醛和苯甲醛的底物亲和力最高,而未检测到甘露醇脱氢酶活性。这些结果以及之前的结果支持了ELI3-2在抗性相关的芳香酸衍生代谢中起重要作用的观点。