【摘要】 通过硫酸铵分级分离和ＳｅｐｈａｄｅｘＧ－１００柱纯化得到的小麦叶片蛋白，可分为两个部分，其对硝酸还原酶（ＮＲ）都有明显的钝化活力；且钝化蛋白部分Ⅱ的钝化活力明显高于同样蛋白含量的部分Ⅰ．小麦叶片中硝酸还原酶钝化蛋白部分Ⅰ和Ⅱ同样对其根中的ＮＲ具有钝化活性。钝化蛋白部分Ⅰ通过聚丙烯酰胺凝胶电泳进一步纯化，达到电泳纯，测得分子量为４７．５ｋ更多还原

【Abstract】 When a crude extract from wheat leaves was fractionated by a combination of ammonium sulfate (30%￣45% saturation) precipatation and Sephadex G 100 filtration,the presence of two NR inactivating proteins was revealed.Both inactivating protein Ⅰ and inactivating protein Ⅱ had a strongly inhibatory effect on nitrate reductase activity from the leaves.The effect of inactivating protein Ⅱ was much higher than that of protein Ⅰ when an equal amount of inactivating protein Ⅰ and Ⅱ was used in the reaction mixture.The NR inactivating proteins from wheat leaves also have inhibatory effect on notrate reductase activity from the roots.With polyacrylamid electrophoresis the more pure inactivating protein I was obtained with the molecular weight of 47.5 kD.更多还原