Figure 4

Enzymatic characteristics of purified rPglA and the truncated enzymes. A, Influence of temperature on β-1,3-glucanase activity. Reactions were carried out at pH 6.0 and temperatures ranging from 35 to 80°C for 20 min. Values were expressed as percentages of maximal activity. B, Thermal stability of rPglA and the truncated derivatives. The enzymes were incubated at 55°C for up to 60 min and the residue enzyme activities were determined under optimal conditions for 20 min. C, Influence of pH on β-1,3-glucanase activity. Reactions were carried out at optimal temperatures for each enzyme for 20 min in buffers of varying pH (2.0-10.0). D, pH stability of rPglA and the truncated derivatives. Purified enzymes were first incubated in buffers of varying pH (2.0-12.0) at 4°C for 4 h, and activity was measured under optimal conditions for 20 min. The buffers (50 mM) used were: glycine-HCl (pH 2.0-4.0), sodium acetate (pH 5.0-7.0), Tris–HCl (pH 7.5-8.5) and glycine-NaOH (pH 9.0-12.0). The measurements were repeated in triplicate.