Cloning, Expression and Enzymatic Characterization of Chitin Deacetylase 4 from Hyphantria Cunea (Drury)

摘要

A novel chitin deacetylase (CDA), HcCDA4, was identified from the American white moth, Hyphantria cunea. The full-length cDNA sequence of HcCDA4 was identified, and the cDNA is 1494bp in length. The HcCDA4 was shown as a 56 kDa protein in E. coli BL21 by SDS-PAGE analysis and the specific antibodies reacting to HcCDA4 were obtained by immunizing rabbits. The insect cells secreting expressed HcCDA4 proteins were used to study enzymatic properties. Results showed that HcCDA4 possessed catalytic activity, and the optimum temperature was 50°C and the optimum pH was 8.0. Under the optimum reaction conditions, the enzyme activities of HcCDA4 protein was 3.44 U·mL~(-1). The enzyme activity is enhanced in the presence of Zn~(2+), Mn~(2+) and Fe~(2+) ions, but inhibited in the presence of Mg~(2+) and Co~(2+) ions, Ca~(2+) showed a trend of increasing first and then decreasing on HcCDA4 enzymatic activity.