High-level production of ChSase ABC I by co-expressing molecular chaperones in Escherichia coli

Chondroitinase ABC I (ChSase ABC I), as a polysaccharide lyase, can catalyze high molecular weight chondroitin sulfate (CS) to low molecular weight glycosaminoglycan which are easier to be absorbed and utilized by organisms. In this study, to enhance the production of ChSase ABC I and avoid the negative influence of tags on its catalytic efficiency, we employed molecular chaperones to co-express with ChSase ABC I. Firstly, different molecular chaperones and their combinations were screened and GroES exhibited the best positive effect. Consecutively, fermentation conditions were optimized to further improve the production. As a result, the production of ChSase ABC I was increased to 4640.44 +/- 896.26 IU/g wet weight, a 2.15-fold higher value when compared with that of control in the same fermentation conditions. After that, to testify the influence of GroES on characterization of ChSase ABC I, the optimal pH and temperature, and kinetic parameters were confirmed. The affinity to substrate of ChSase ABC I with GroES assist was increased 7 folds as compared to the native ChSase ABC I, and ChSase ABC I with GroES co-expression still has high catalytic activity. This work not only presents to date the first achievement of ChSase ABC I high-level production with molecular chaperone co-expression, but also serves as a potential basis for its industrial application. (C) 2018 Published by Elsevier B.V.