Chitinase Genes LbCHI31 and LbCHI32 from Limonium bicolor Were Successfully Expressed in Escherichia coli and Exhibit Recombinant Chitinase Activities
Figure 3
Enzymatic properties of four different recombinant chitinases. Dark blue: enzymatic properties of recombinant intracellular inrCHI31; pink: enzymatic properties of recombinant extracellular exrCHI31; purple: enzymatic properties of recombinant intracellular inrCHI32; Powder blue: enzymatic properties of recombinant intracellular exrCHI32. The precipitates of transformants BL21-inCHI31 and BL21-inCHI32 were used to measure chitinase activity. The culture supernatants of transformants BL21-exCHI31 and BL21-exCHI32 were used to measure chitinase activity. The supernatant was used as a control after being boiled at 100°C for 20 min. (a) Regulation of enzyme production of four transformants BL21-inCHI31, BL21-exCHI31, BL21-inCHI32, and BL21-exCHI32. The four transformants were induced by 1 mM IPTG at 30°C for 2 to 8 h, with 1 h intervals. The enzyme activities at different induced times were measured. (b) The effects of temperature on four recombinant activities. The chitinase activities were measured between 35°C and 80°C for 30 min at 5°C intervals (pH = 4.5). (c) The effects of temperature on the stability of four recombinases. The enzymatic solution (pH = 4.5) was incubated between 35°C and 80°C for 30 min at 5°C intervals, and the remaining activity was then measured. (d) The effects of pH on four recombinase enzymatic activities. Enzymatic activity was measured in the reaction buffer at different pH values from 3 to 12 at 1-unit intervals. All experiments were performed three times.
