Purification and Characterization of an Indican-hydrolyzing β-glucosidase from Agrobacterium tumefaciens

© 2012 The Korean Society for Biotechnology and Bioengineering Abstract:1)Indican (indoxyl-β-D-glucoside) is a colorless natural compound and can be used as a precursor for the production of indigo. This production step only require an enzyme, β-glucosidase, that readily screened from microbial resource by using selective media supplemented with indican as a sole carbon source. Agrobacterium tumefaciens was well grown in this media and thus presumed to produce a related enzyme. The corresponding gene, encoding a protein with a calculated molecular mass of 51 kDa, was cloned and overexpressed as MBP fusion proteins. The purified enzyme was determined to be a dimer and showed the maximum activity for indican at pH 7.0 and 40℃. The kinetic parameters for indican, Km and Vmax, were determined to be 1.4 mM and 373.8 µM/min/mg, respectively. The conversion yiel