Cloning and expression of Lentinula edodes cellobiohydrolase gene in E. coli and characterization of the recombinant enzyme

摘要

A gene encoding cellobiohydrolase CEL7A was successfully isolated from the L. edodes mushroom strain N127 using RT-PCR. The deduced amino acid sequence encoded by cel7A showed high homology with the sequence of glycoside hydrolase family 7. To confirm the gene sequence encoding the CEL7A the cloned gene was expressed in E. coli. For the first time the cel7A gene from the L. edodes was expressed in E. coli and characterized. The recombinant CEL7A has the ability to hydrolyze Avicel, Filter paper, p-Nitrophenyl -D-lactopyranoside (pNP-Lac) and p-Nitrophenyl -D-cellobioside (pNP-Cel). The activity of the cloned enzyme towards carboxymethylcellulose (CMC) is much lower. It showed an optimal working condition at 0C and pH 7. 50