Krest I, Keusgen M
Institut für Pharmazeutische Biologie, Universität Bonn, Germany.
Planta Med. 1999 Mar;65(2):139-43. doi: 10.1055/s-1999-13975.
Alliinase (EC 4.4.1.4) has been isolated from commercially available garlic (Allium sativum L., Alliaceae) powder and was investigated with respect to its use as ingredient of herbal remedies. The enzyme was purified to apparent homogeneity and results were compared with those obtained from a sample of fresh A. sativum var. pekinense. The purification of the enzyme involved a gel filtration step as well as affinity chromatography on concanavalin-A agarose. Vmax using L-(+)-alliin as substrate (252 mumol min-1 mg-1) was at the lower range of data given in the literature (214-390 mumol min-1 mg-1). L-(-)-Alliin was also accepted as substrate (54 mumol min-1 mg-1). Vmax for alliinase from A. sativum var. pekinense was at 332 mumol min-1 mg-1 and 90 mumol min-1 mg-1 for L-(+)- and L-(-)-alliin, respectively. The Km values for alliinase from garlic powder were estimated to be 1.6 mM for L-(+)-alliin and 2.8 mM for L-(-)-alliin. In contrast to literature values, both temperature and pH optima were somewhat higher (36 degrees C and pH 7.0 versus 33 degrees C and pH 6.5, respectively). The enzyme was found to be active in a range from pH 5 to pH 10. Gel electrophoresis gave evidence that the alliinase obtained from garlic powder consisted of two slightly different subunits with molecular weights of 53 and 54 kDa whereas alliinase obtained from fresh garlic consists of two identical subunits. It is assumed that the alliinase gets significantly altered during the drying process of garlic powder but is still capable to convert alliin to allicin.
蒜氨酸酶（EC 4.4.1.4）已从市售大蒜（葱属植物大蒜，葱科）粉末中分离出来，并对其作为草药成分的用途进行了研究。该酶被纯化至表观纯一，其结果与从新鲜的紫皮蒜样品中获得的结果进行了比较。酶的纯化过程包括凝胶过滤步骤以及伴刀豆球蛋白A琼脂糖亲和层析。以L-(+)-蒜氨酸为底物时的最大反应速度（Vmax）为252 μmol min⁻¹ mg⁻¹，处于文献报道数据的较低范围（214 - 390 μmol min⁻¹ mg⁻¹）。L-(-)-蒜氨酸也可作为底物（54 μmol min⁻¹ mg⁻¹）。紫皮蒜蒜氨酸酶对L-(+)-蒜氨酸和L-(-)-蒜氨酸的Vmax分别为332 μmol min⁻¹ mg⁻¹和90 μmol min⁻¹ mg⁻¹。大蒜粉中蒜氨酸酶对L-(+)-蒜氨酸和L-(-)-蒜氨酸的米氏常数（Km）估计分别为1.6 mM和2.8 mM。与文献值相比，温度和pH最适值均略高（分别为36℃和pH 7.0，而文献值为33℃和pH 6.5）。发现该酶在pH 5至pH 10的范围内具有活性。凝胶电泳表明，从大蒜粉中获得的蒜氨酸酶由两个分子量分别为53 kDa和54 kDa的略有不同的亚基组成，而从新鲜大蒜中获得的蒜氨酸酶由两个相同的亚基组成。据推测，蒜氨酸酶在大蒜粉干燥过程中发生了显著变化，但仍能够将蒜氨酸转化为蒜素。
