AUTHOR=Byrt Caitlin S., Cahyanegara Ricky , Grof Christopher P.

TITLE=Plant Carbohydrate Binding Module Enhances Activity of Hybrid Microbial Cellulase Enzyme

JOURNAL=Frontiers in Plant Science

VOLUME=3

YEAR=2012

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2012.00254

DOI=10.3389/fpls.2012.00254

ISSN=1664-462X

ABSTRACT=<p>A synthetic, highly active cellulase enzyme suitable for <italic>in planta</italic> production may be a valuable tool for biotechnological approaches to develop transgenic biofuel crops with improved digestibility. Here, we demonstrate that the addition of a plant derived carbohydrate binding module (CBM) to a synthetic glycosyl hydrolase improved the activity of the hydrolase in releasing sugar from plant biomass. A CEL-HYB1-CBM enzyme was generated by fusing a hybrid microbial cellulase, CEL-HYB1, with the CBM of the tomato (<italic>Solanum lycopersicum</italic>) SlCel9C1 cellulase. CEL-HYB1 and CEL-HYB1-CBM enzymes were produced <italic>in vitro</italic> using <italic>Pichia pastoris</italic> and the activity of these enzymes was tested using carboxymethylcellulose, MUC, and native crystalline cellulose assays. The presence of the CBM substantially improved the endoglucanase activity of CEL-HYB1, especially against the native crystalline cellulose encountered in <italic>Sorghum bicolor</italic> plant cell walls. These results indicate that addition of an endogenous plant derived CBM to cellulase enzymes may enhance hydrolytic activity.</p>