Journal of Insect Science (2009) 9 (4), 1-13

D. Yapi, D. Gnakri, S. Niamke and L. Kouame (2009)
Purification and biochemical characterization of a specific ß-glucosidase from the digestive fluid of larvae of the palm weevil, Rhynchophorus palmarum
Journal of Insect Science 9 (4), 1-13
Abstract: A ß-glucosidase was purified from the digestive fluid of the palm weevil Rhynchophorus palmarum L. (Coleoptera: Curculionidae) by chromatography on anion-exchange, gel filtration, and hydrophobic interaction columns. The preparation was shown to be homogeneous on polyacrylamide gels. ß-glucosidase is a monomeric protein with a molecular weight of 58 kDa based on its mobility in SDS-PAGE and 60 kDa based on gel filtration. Maximal ß-glucosidase activity occurred at 55°C and pH 5.0. The purified ß-glucosidase was stable at 37°C and its pH stability was in the range of 5.0-6.0. The enzyme readily hydrolyzed p-nitrophenyl-ß-D-glucoside, cellobiose, cellodextrins and required strictly ß-gluco configuration for activity. It cleaved glucose-glucose beta-(1-4) linkages better than ß-(1-2), ß-(1-3) and ß-(1-6) linkages. The catalytic efficiency (K_cat/K_M) values for p-nitrophenyl-ß-D-glucoside and cellobiose were respectively 240.48 mM⁻¹s⁻¹ and 134.80 mM⁻¹s⁻¹. Beta-glucosidase was capable of catalysing transglucosylation reactions. The yield of glucosylation of 2-phenylethanol (20 %), catalysed by the beta-glucosidase in the presence of cellobiose as glucosyl donor, is lower than those reported previously with conventional sources of beta-glucosidases. In addition, the optimum pH is different for the hydrolysis (pH 5.0) and transglucosylation reactions (pH 6.6).
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Link to article at publishers website
Database assignments for author(s): Lucien Patrice Kouame

Research topic(s) for pests/diseases/weeds:
molecular biology - genes

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Rhynchophorus palmarum