Characterization of Partially Purified Peroxidase from Fingerroot (Boesenbergia Rotunda (L.) Mansf.)

Abstract

Peroxidase from fingerroot was partially purified and characterized for potential use in analytical applications. The procedure began with crude extract preparation, followed by ammonium sulfate fractionation and concanavalin A-sepharose 4B affinity chromatography. The fraction of protein precipitated at 20-40% saturation of ammonium sulfate possessed the highest specific activity of 7.74 units/ mg. This fraction was subsequently purified further using affinity binding of peroxidase, a glycosylated enzyme, to Concanavalin A-sepharose 4B column. The chromatographic step produced peroxidase with specific activity of 55.33 units/ mg and resulted in 19.34 fold of purification. Invetigation on optimal conditions revealed pH optimum to be at 6 and temperature optimum to be at 40 °C. After 5 hour incubation fingerroot peroxidase retained 60% of activity at pH 6 and 40 °C. Activity of the enzyme rapidly dropped at pH 2, while temperature at 70 °C and above inactivated the enzyme within the first hour. At concentration of 5 mM CaCl2, MgCl2, MnCl2, NaCl and ZnCl2 did not show notable effect on peroxidase activity, whereas CuCl2 and FeCl2 moderately inhibited the activity of peroxidase. AlCl3 and FeCl3 at 5 mM highly inhibited the activity of the enzyme up to 70%. 