Phenylalanine hydroxylase(PAH)derived from Chromobacterium violaceum has potential pharmaceutical value due to its simple structure and the closer property to human PAH. We cloned the pah gene from C. violaceum and constructed recombinant expression vcectors pET24a-pah, finally, the pah gene was efficiently expressed in Escherichia coli BL21(DE3). The specific activity of recombination protein was 503.2 U/mg after purification. The studies of enzymatic properties showed that the enzyme displayed maximum activity at 40℃, and its half-life was 15 min at 50℃. The optimal pH was pH7.5, and the enzyme activity was stable at the range of pH6-8. Under the conditions of 37℃and pH7.5, its Km was 1.5 mmol/L, Vmax was 0.5 mmol/min, kcat was 5.05/s, and the catalytic efficiency(kcat/Km)was 3.37 L/mmol·s.%来源于紫色色杆菌（Chromobacterium violaceum）的苯丙氨酸羟化酶结构简单，性质更接近于人的苯丙氨酸羟化酶，具有潜在的医药应用价值。从紫色色杆菌基因组中克隆得到苯丙氨酸羟化酶基因pah。构建重组表达载体pET24a-pah，并在Escherichia coli BL21（DE3）中实现高效表达。离子层析纯化后，重组蛋白比酶活高达503.2 U/mg。酶学性质研究显示，该重组酶的最适温度为40℃左右，50℃时PAH的半衰期为15 min；最适pH在7.5左右，在pH6-8范围内较稳定。37℃，pH7.5条件下， Km值为1.5 mmol/L，Vmax为0.5 mmol/min，kcat为5.05/s，催化效率kcat/Km为3.37 L/mmol·s。
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