FIG. 3.
Effect of pH on the binding of chitinase A1 and ChBDChiA1 to regenerated chitin. Assay mixtures contained 1 mg (dry weight) of regenerated chitin and 1 nmol of either chitinase A1 (70 μg) or ChBDChiA1 (6.5 μg) in 1 ml of buffers with various pHs. The buffers used in this experiment were 20 mM sodium citrate (pH 2.0 to 6.0), sodium phosphate (pH 7.0), Tris-HCl (pH 8.0), glycine-NaOH (pH 9.0 and 10.0), and disodium hydrogen phosphate-NaOH (pH 11 and 12). Assay mixtures were incubated on ice for 1 h for chitinase A1 and 3 h for ChBDChiA1. ●, chitinase A1; ×, ChBDChiA1.