title: Catalytic efficiency of chitinase-D on insoluble chitinous substrates was improved by fusing auxiliary domains.
abstract: Chitin is an abundant renewable polysaccharide, next only to cellulose. Chitinases are important for effective utilization of this biopolymer. Chitinase D from Serratia proteamaculans (SpChiD) is a single domain chitinase with both hydrolytic and transglycosylation (TG) activities. SpChiD had less of hydrolytic activity on insoluble polymeric chitin substrates due to the absence of auxiliary binding domains. We improved catalytic efficiency of SpChiD in degradation of insoluble chitin substrates by fusing with auxiliary domains like polycystic kidney disease (PKD) domain and chitin binding protein 21 (CBP21). Of the six different SpChiD fusion chimeras, two C-terminal fusions viz. ChiD+PKD and ChiD+CBP resulted in improved hydrolytic activity on α- and β-chitin, respectively. Time-course degradation of colloidal chitin also confirmed that these two C-terminal SpChiD fusion chimeras were more active than other chimeras. More TG products were produced for a longer duration by the fusion chimeras ChiD+PKD and PKD+ChiD+CBP.
authors.affiliation: Department of Plant Sciences, School of Life Sciences, University of Hyderabad, Gachibowli, Hyderabad, India.
authors.forename: Jogi
authors.initials: J
authors.lastname: Madhuprakash
authors.affiliation: Department of Plant Biology and Biotechnology, Westphalian Wilhelm's-University of Münster, Münster, Germany.
authors.forename: Nour Eddine
authors.initials: NE
authors.lastname: El Gueddari
authors.affiliation: Department of Plant Biology and Biotechnology, Westphalian Wilhelm's-University of Münster, Münster, Germany.
authors.forename: Bruno M
authors.initials: BM
authors.lastname: Moerschbacher
authors.affiliation: Department of Plant Sciences, School of Life Sciences, University of Hyderabad, Gachibowli, Hyderabad, India.
authors.forename: Appa Rao
authors.initials: AR
authors.lastname: Podile
mesh_terms: D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D055162:Biocatalysis; D002686:Chitin / Q000378:metabolism*; D002688:Chitinases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D017434:Protein Structure, Tertiary; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D012705:Serratia / Q000201:enzymology*; D013379:Substrate Specificity
chemical_list: D001426:Bacterial Proteins; D011993:Recombinant Fusion Proteins; D002686:Chitin; D002688:Chitinases