Fusion of cellulose binding domain to the catalytic domain improves the activity and conformational stability of chitinase in Bacillus licheniformis DSM13

Chitinase from Bacillus licheniformis DSM13 consists of an N-terminal catalytic domain (GH) and a C-terminal chitin binding domain (ChBD). A deletion mutant BliGH and a hybrid chitinase BliGH-CeBD were developed using polymerase chain reaction (PCR) to study the role of substrate-binding domain. Both recombinant chitinases retained their ability to bind to glycol-chitin (GC). BliGH was more effective on colloidal chitin (CC) than BliGH-CeBD as evident from the increased Vmax and kcat values. The fusion of CeBD improved the affinity to colloidal chitin, activity and conformational stability in BliGH-CeBD when compared with deletion mutant BliGH.