Chitinase is an enzyme catalyzing hydrolysis of 1 ,4-beta-glycoside bonds in chitin and produced by a wide variety of organisms. Chitinase has been used in controlling pathogenic fungi in plants and insects. Recently, the gene encoding the chitinase from several microbial strains have been cloned and expressed in lieterologous host cells and recombinant enzymes have been purified and characterized. In this study, a gene coding for a chitinase, of the glycosyl hydrolase family 18 and derived from L. lecanii 43H, was cloned and sequenced. The cDNA sequence, 1269 bp, and its putative chitinase, a 423 aa protein with a predicted molecular mass 45 kDa and a pH 6.1 exhibited 99.9 percent identities with cDNA sequences their corresponding chitinase from L. lecanii strains from the GenBank. The nucleotide sequence encoding recombinant chitinase from L. lecanii 43H has been,deposited in the GenBank with an accession number of JX665045. The cDNA was overexpressed in P. pastoris X33 under the control of an AOXI promoter, using an expression vector pPICZaA. The transformant expressing the highest level of the chitinase (1.11 Ulml supernatant) was selected. The recombinant chitinase was produced at the highest level in YP medium after induction of 1.5 percent methanol for 96h. The molecular mass of purified recombinant chitinase, determined by SDS-PAGE, was 45 kDa, with a specific activity of 165.7 Ulmg protein. Optimum temperature and pH for the enzyme activity were observed at 40°C and 5,5, respectively. Thus, based on molecular mass, recombinant chitinase of L. lecanii 43H is classified group III with molecular weight of 40-50 kDa, it could be an endochitinase. This result was similar to some previous study.
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