Determination of substrate specificity
To determine the substrate specificity of ChiA, a reaction mix-ture composed of ChiA (0.4 M) and 1% of each substrate in a finalvolume of 1.0 mL was incubated at 20◦C for 2 h. After incubation,the concentration of reducing sugar produced by the reaction wasdetermined [19] by comparison to a standard curve of GlcNAc.