College of Biology and Environmental Engineering, Zhejiang Shuren University, Hangzhou 310015, People's Republic of China.
Appl Biochem Biotechnol. 2010 Oct;162(4):966-74. doi: 10.1007/s12010-009-8787-5. Epub 2009 Oct 2.
A soluble 3-ketovalidoxylamine A C-N lyase from Stenotrophomonas maltrophilia was purified to 367.5-fold from the crude enzyme, with a yield of 16.4% by column chromatography on High S IEX, Methyl HIC, High Q IEX, and Sephadex G 100. The molecular mass of the enzyme was estimated to be 34 kDa by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and the enzyme was a neutral protein having an isoelectric point value at pH 7.0. The optimal pH of 3-ketovalidoxylamine A C-N lyase was around 7.0. The enzyme was stable within a pH range of 7.0-10.5. The optimal temperature was found to be near 40 degrees C, and the enzyme was sensitive to heat. The enzyme was completely inhibited by ethylenediaminetetraacetic acid, and it was reversed by Ca2+. The product, p-nitroaniline, inhibited the enzyme activity significantly at low concentration. The enzyme has C-N lyase activity and C-O lyase activity, and need 3-keto groups. The apparent K (m) value for p-nitrophenyl-3-ketovalidamine was 0.14 mM.
从嗜麦芽寡养单胞菌中纯化得到一种可溶性 3-酮基缬氨酰基 validoxylamine A C-N 裂解酶，经 High S IEX、Methyl HIC、High Q IEX 和 Sephadex G 100 柱层析，酶活比活力达到 367.5 倍，收率为 16.4%。该酶的相对分子质量通过十二烷基硫酸钠-聚丙烯酰胺凝胶电泳估算为 34 kDa，为中性蛋白，等电点 pH 值为 7.0。3-酮基缬氨酰基 validoxylamine A C-N 裂解酶的最适 pH 值约为 7.0。该酶在 pH 值 7.0-10.5 范围内稳定。最适温度接近 40°C，且该酶对热敏感。酶被乙二胺四乙酸完全抑制，可被 Ca2+ 逆转。产物对硝基苯胺在低浓度时可显著抑制酶活性。该酶具有 C-N 裂解酶和 C-O 裂解酶活性，需要 3-酮基团。对硝基苯-3-酮缬氨酰基 validoxylamine 的表观 K (m) 值为 0.14 mM。
