Partial Purification and Characterization of an Inducible Indole-3-Acetyl-L-Aspartic Acid Hydrolase from Enterobacter agglomerans
作者:J. C. Chou、G. A. Kuleck、J. D. Cohen、W. W. Mulbry
DOI:10.1104/pp.112.3.1281
日期:1996.11.1
the hydrolase activity was inhibited to 80% by 1 mM dithiothreitol and to 60% by 1 mm CuSO4; the activity was increased by 40% with 1 mM MnSO4. However, in extraction buffer with no trace elements, the hydrolase activity was inhibited to 50% by either 1 mM dithiothreitol or 1% Triton X-100 (Sigma). These results suggest that disulfide bonding might be essential for enzyme activity. Purification of the
据信吲哚-3-乙酰基氨基酸共轭水解酶在调节植物中吲哚-3-乙酸(IAA)的代谢中很重要,因此具有改变植物IAA代谢的潜在用途。为了分离出表现出显着的吲哚-3-乙酰基-天冬氨酸(IAA-Asp)水解酶活性的细菌菌株,在IAA-Asp充当唯一碳和氮源的条件下培养污水污泥接种物。一种分离物,即成团肠杆菌,显示出可被IAA-L-Asp或N-乙酰基-L-Asp诱导的水解酶活性,但不能被IAA,(NH4)2SO4,尿素或吲哚乙酰胺诱导。在总共17种IAA偶联物作为潜在底物进行测试中,该酶对IAA-L-Asp具有很高的底物特异性。动力学数据的底物浓度曲线和Lineweaver-Burk图显示IAA-L-Asp的Michaelis常数为13.5 mM。该酶的最佳pH在8.0至8.5之间。在含有0.8 mM Mg2 +的提取缓冲液中,水解酶的活性被1 mM二硫苏糖醇抑制到80%,被1 mm CuSO4抑制到60%。用1