Recombinant expression of a chitosanase and its application in chitosan oligosaccharide production.
Recently, considerable attention has been focused on chitosan oligosaccharides (COSs) due to their various biological activities. COSs can be prepared by enzymatic degradation of chitosan, which is the deacetylation product of chitin, one of the most abundant biopolymers in nature. In the current study, we recombinantly expressed a chitosanase and used it for COS preparation. A bacillus-derived GH8 family chitosanase with a 6xHis tag fused at its N-terminal was expressed in the Escherichia coli strain BL21(DE3) as a soluble and active form. Its expression level could be as high as 500 mg/L. Enzymatic activity could reach approximately 140,000 U/L under our assay conditions. The recombinant chitosanase could be purified essentially to homogeneity by immobilized metal-ion affinity chromatography. The enzyme could efficiently convert chitosan into monomer-free COS: 1g of enzyme could hydrolyze about 100 kg of chitosan. Our present work has provided a cheap chitosanase for large-scale COS production in industry.
Liu
Ya-Li
YL
Zhejiang Feng'an Biopharmaceutical, Xianju 317300, China.
Jiang
Shu
S
Ke
Zu-Min
ZM
Wu
Hai-Shui
HS
Chi
Cheng-Wu
CW
Guo
Zhan-Yun
ZY
D048271:Chitosan / Q000378:metabolism*; D002846:Chromatography, Affinity; D002855:Chromatography, Thin Layer; D004795:Enzyme Stability; D005822:Genetic Vectors; D006026:Glycoside Hydrolases / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D011994:Recombinant Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D013696:Temperature
D011994:Recombinant Proteins; D048271:Chitosan; D006026:Glycoside Hydrolases; C019868:chitosanase