title: Combining chitinase C and N-acetylhexosaminidase from Streptomyces coelicolor A3(2) provides an efficient way to synthesize N-acetylglucosamine from crystalline chitin.
abstract: The enzymatic bioconversion of chitin is of considerable interest for the natural production of bioactive compounds such as chitooligosaccharides and N-acetyl-d-glucosamine (GlcNAc). Key enzymes are involved in the natural processing of chitin, hydrolyzing this abundant biopolymer to yield chitooligosaccharides with substantial value to the medicinal and biotechnological fields. In this study, chitinase C (ScChiC) from the soil bacterium and chitin decomposer Streptomyces coelicolor A3(2) was expressed, purified and characterized. We also optimized a Streptomyces lividans system generating ScChiC expression yields nearly 500-fold higher than the previously reported heterologous expression in Escherichia coli. The purified enzyme was found to be stable below 55°C for a broad range of pH values (pH 3.5-9) and exhibited high activity against chitin and chitooligosaccharides to form chitobiose (C2) as main product. Crab shell chitin hydrolysis profiles also revealed that ScChiC catalyzes the bioconversion of chitopolysaccharides through an endo-nonprocessive mode of action. When combining ScChiC with an N-acetylhexosaminidase from S. coelicolor A3(2) (ScHEX) in an assay using crude extracts and crystalline chitin as substrate, GlcNAc was generated as final product with a yield over 90% after 8h incubation. This chitin hydrolysis yield represents one of the most efficient enzyme bioconversion of chitopolysaccharides to GlcNAc characterized to date, making the S. coelicolor ScChiC-ScHEX pair a potentially suitable contender for the viable industrial production of this important bioactive compound.
authors.affiliation: INRS-Institut Armand-Frappier, Université du Québec, 531 Boul. des Prairies, Laval, Québec H7V 1B7, Canada.
authors.forename: Nhung
authors.initials: N
authors.lastname: Nguyen-Thi
authors.affiliation: INRS-Institut Armand-Frappier, Université du Québec, 531 Boul. des Prairies, Laval, Québec H7V 1B7, Canada; PROTEO, The Québec Network for Research on Protein Function, Engineering, and Applications, 1045 Avenue de la Médecine, Université Laval, Québec, Québec, G1V 0A6, Canada; GRASP, The Groupe de Recherche Axé sur la Structure des Protéines, 3649 Promenade Sir William Osler, McGill University, Montréal, Québec, H3G 0B1, Canada. Electronic address: nicolas.doucet@iaf.inrs.ca.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Doucet
mesh_terms: D000117:Acetylglucosamine / Q000096:biosynthesis* / Q000378:metabolism; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D002686:Chitin / Q000031:analogs & derivatives / Q000737:chemistry / Q000378:metabolism*; D002688:Chitinases / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D048271:Chitosan; D003001:Cloning, Molecular; D004187:Disaccharides / Q000378:metabolism; D004789:Enzyme Activation; D004795:Enzyme Stability; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D005944:Glucosamine / Q000378:metabolism; D006596:Hexosaminidases / Q000378:metabolism*; D006868:Hydrolysis; D009844:Oligosaccharides; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism; D012988:Soil Microbiology; D048372:Streptomyces coelicolor / Q000201:enzymology / Q000235:genetics / Q000378:metabolism*; D048170:Streptomyces lividans / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D004187:Disaccharides; D009844:Oligosaccharides; D010940:Plant Proteins; D011994:Recombinant Proteins; C493484:oligochitosan; D002686:Chitin; C032438:chitobiose; D048271:Chitosan; D006596:Hexosaminidases; D002688:Chitinases; C119825:chitinase C; D005944:Glucosamine; D000117:Acetylglucosamine
keywords: Bioconversion; Biotechnology; Carbohydrates; Enzyme; Glucosamine