RHA-P: isolation, expression and characterization of a bacterial α-L-rhamnosidase from Novosphingobium sp. PP1Y.

Publication date: Available online 3 October 2016 Source:Journal of Molecular Catalysis B: Enzymatic Author(s): Federica De Lise, Francesca Mensitieri, Vincenzo Tarallo, Nicola Ventimiglia, Roberto Vinciguerra, Annabella Tramice, Roberta Marchetti, Elio Pizzo, Eugenio Notomista, Valeria Cafaro, Antonio Molinaro, Leila Birolo, Alberto Di Donato, Viviana Izzo α-l-Rhamnosidases (α-RHAs) are a group of glycosyl hydrolases of biotechnological potential in industrial processes, which catalyze the hydrolysis of α-l-rhamnose terminal residues from several natural compounds. A novel α−RHA activity was identified in the crude extract of Novosphingobium sp. PP1Y, a marine bacterium able to grow on a wide range of aromatic polycyclic compounds. In this work, this α-RHA activity was isolated from the native microorganism and the corresponding orf was identified in the completely sequenced and annotated genome of strain PP1Y. The coding gene was expressed in Escherichia coli, strain BL21(DE3), and the recombinant protein, rRHA-P, was purified and characterized as an inverting monomeric glycosidase of ca. 120kDa belonging to the GH106 family. A biochemical characterization of this enzyme using pNPR as substrate was performed, which showed that rRHA-P had a moderate tolerance to organic solvents, a significant thermal stability up to 45°C and a catalytic efficiency, at pH 6.9, significantly higher than other bacterial α-RHAs described in literature. Moreover, rRHA-P ...
Source: Journal of Molecular Catalysis B: Enzymatic - Category: Biochemistry Source Type: research