Abstract
Chitinase B was purified from a culture medium of Ralstonia sp. A-471 by precipitation with (NH4)2SO4 and column chromatography with DEAE-Toyopearl 650M and Sephacryl S-200. The purified enzyme was homogeneous on SDS–PAGE. The molecular weight was 45,000 by SDS–PAGE. The optimum pH was 5.0 and stable pH was from 5.0 to 10.0. In the early stage of the reaction, chitinase B produced β-anomer of (GlcNAc)2 from the substrate (GlcNAc)6, whereas (GlcNAc)4 produced almost at equilibrium, indicating that the enzyme predominantly hydrolyzes the second glycosidic linkage from the nonreducing end of (GlcNAc)6.
