Purification and Characterization of a Novel α-L-Arabinofuranosidase from Pichia capsulata X91

Abstract

An intracellular α-L-arabinofuranosidase from Pichia capsulata X91 was purified and characterized. The enzyme was purified to homogeneity from a cell-free extract by ammonium sulfate treatment, Concanavalin A-Sepharose, ion-exchange chromatography with DEAE Bio-Gel A agarose, arabinose-Sepharose 6B affinity chromatography, and hydroxyapatite column chromatography. The apparent molecular mass of the enzyme was estimated to be 250 kDa by native-PAGE. The enzyme molecule was suggested to be a tetramer with a subunit molecular mass of 72 kDa by SDS-PAGE. The enzyme had an isoelectric point at 5.1, and was most active at pH 6.0 and at around 50°C. The α-L-arabinofuranosidase was active at ethanol concentrations of wine. The enzyme was inhibited by Cu²⁺, Hg²⁺, and p-chloromercuribenzoate. The enzyme hydrolyzed beet arabinan and arabinogalactan, and efficiently released monoterpenols from an aroma precursor extracted from Muscat grape juice. A considerable amount of monoterpenols was produced in the Muscat wine coupled with the enzyme addition.

• α-L-arabinofuranosidase
• Pichia capsulata
• aroma enhancement
• monoterpenol