Purification and characterization of cyanogenic β-glucosidase from wild apricot (Prunus armeniaca L.)

Abstract

Abstract β-Glucosidase catalyzes the sequential breakdown of cyanogenic glycosides in cyanogenic plants. The β-glucosidase from Prunus armeniaca L. was purified to 8-fold, and 20% yield was obtained, with a specific activity of 281 U/mg protein. The enzyme showed maximum activity in 0.15 M sodium citrate buffer, pH 6, at 35 °C with p -nitrophenylglucopyranoside as substrate. The β-glucosidase from wild apricot was used successfully for the saccharification of cellobiose into D-glucose. This enzyme has a V max of 131.6 μmol min −1 mg −1 protein, K m of 0.158 mM, K cat of 144.8 s −1 , K cat / K m of 917.4 mM −1 s −1 , and K m / V max of 0.0012 mM min mg μmole −1 , using cellobiose as substrate. The half-life, deactivation rate coefficient, and activation energy of this β-glucosidase were 12.76 h, 1.509 × 10 −5 s −1 , and 37.55 kJ/mol, respectively. These results showed that P. armeniaca is a potential source of β-glucosidase, with high affinity and catalytic capability for the saccharification of cellulosic material.