Whitt D D, Klug M J, DeMoss R D
Arch Microbiol. 1979 Aug 6;122(2):169-75. doi: 10.1007/BF00411356.
The conditions for synthesis, purification, and properties of tryptophanase by a marine organism (Vibrio K-7) were studied. Tryptophanase was induced by tryptophan and its analogs, and partially repressed by 0.5% glucose or glycerol. NaCl (0.4 M) was required for optimal growth and tryptophanase activity in whole cells. The enzyme was purified to 92% homogeneity by heat treatment, hydroxyapatite chromatography and fractionation with ammonium sulfate. This tryptophanase has been found to have kinetic properties similar to the tryptophanase from other microorganisms. It carries out both alpha, beta-elimination reactions (using tryptophan, serine, cysteine and S-methylcysteine as substrates) and beta-replacement reactions (forming tryptophan from indole and serine, cysteine or S-methyl-cysteine). The enzyme has a sedimentation coefficient of 9.2S and requires pyridoxal 5'-phosphate as a cofactor. The optimal pH for the tryptophanase reaction is pH 8.0.
研究了一种海洋生物（弧菌K-7）合成、纯化色氨酸酶的条件及其性质。色氨酸酶由色氨酸及其类似物诱导产生，并被0.5%的葡萄糖或甘油部分抑制。在全细胞中，最佳生长和色氨酸酶活性需要0.4M的NaCl。通过热处理、羟基磷灰石色谱和硫酸铵分级分离，该酶被纯化至92%的纯度。已发现这种色氨酸酶具有与其他微生物的色氨酸酶相似的动力学性质。它既可以进行α,β-消除反应（以色氨酸、丝氨酸、半胱氨酸和S-甲基半胱氨酸为底物），也可以进行β-取代反应（由吲哚和丝氨酸、半胱氨酸或S-甲基半胱氨酸形成色氨酸）。该酶的沉降系数为9.2S，需要磷酸吡哆醛作为辅因子。色氨酸酶反应的最佳pH值为8.0。
