Colrat S, Latche A, Guis M, Pech JC, Bouzayen M, Fallot J, Roustan JP
Ecole Nationale Superieure Agronomique Unite, Associee, Institut National de la Recherche Agronomique, BP 107, 31326 Castanet-Tolosan cedex, France.
Plant Physiol. 1999 Feb;119(2):621-6. doi: 10.1104/pp.119.2.621.
Eutypine (4-hydroxy-3-[3-methyl-3-butene-1-ynyl] benzaldehyde) is a toxin produced by Eutypa lata, the causal agent of eutypa dieback in the grapevine (Vitis vinifera). Eutypine is enzymatically converted by numerous plant tissues into eutypinol (4-hydroxy-3-[3-methyl-3-butene-1-ynyl] benzyl alcohol), a metabolite that is nontoxic to grapevine. We report a four-step procedure for the purification to apparent electrophoretic homogeneity of a eutypine-reducing enzyme (ERE) from etiolated mung bean (Vigna radiata) hypocotyls. The purified protein is a monomer of 36 kD, uses NADPH as a cofactor, and exhibits a Km value of 6.3 &mgr;M for eutypine and a high affinity for 3- and 4-nitro-benzaldehyde. The enzyme failed to catalyze the reverse reaction using eutypinol as a substrate. ERE detoxifies eutypine efficiently over a pH range from 6.2 to 7.5. These data strongly suggest that ERE is an aldehyde reductase that could probably be classified into the aldo-keto reductase superfamily. We discuss the possible role of this enzyme in eutypine detoxification.
刺盘孢菌素（4-羟基-3-[3-甲基-3-丁烯-1-炔基]苯甲醛）是由喙孢壳菌产生的一种毒素，喙孢壳菌是葡萄（葡萄属）葡萄藤上致死溃疡病的病原体。刺盘孢菌素被许多植物组织酶促转化为刺盘孢醇（4-羟基-3-[3-甲基-3-丁烯-1-炔基]苄醇），一种对葡萄无毒的代谢产物。我们报道了一种从黄化绿豆（绿豆）下胚轴中纯化刺盘孢菌素还原酶（ERE）至表观电泳纯的四步方法。纯化后的蛋白质是一种36kD的单体，以NADPH作为辅因子，对刺盘孢菌素的Km值为6.3μM，对3-和4-硝基苯甲醛具有高亲和力。该酶不能以刺盘孢醇为底物催化逆反应。ERE在pH值6.2至7.5的范围内能有效地使刺盘孢菌素解毒。这些数据强烈表明ERE是一种醛还原酶，可能属于醛酮还原酶超家族。我们讨论了这种酶在刺盘孢菌素解毒中的可能作用。
