Biochemical characterization of Santalum album (Chandan) leaf peroxidase

Abstract

The Santalum peroxidase was extracted from the leaves and precipitated with double volume of chilled acetone. The optimum percent relative activity for the Santalum peroxidase was observed at pH 5.0 and 50°C temperature. The Santalum peroxidase per cent relative activity was stimulated in the presence of phenolic compounds like ferrulic acid and caffeic acids; however, indole-3-acetic acid (IAA) and protocatechuic acid act as inhibitors. All divalent cations Fe 2+ , Mn 2+ , Mg 2+ , Cu 2+ and Zn 2+ stimulate the relative activity of the Santalum peroxidase at concentration of 2.0 μM. Amino acids like L-alanine and L-valine activate the per cent relative activity, while L-proline and DL-methionine showed moderate inhibition for the Santalum peroxidase. However, a very low a concentration of cysteine acts as a strong inhibitor of Santalum peroxidase at the concentration of 0.4 mM. Native polyacrylamide gel electrophoresis (Native-PAGE) was performed for isoenzyme determination and two bands were observed. K m and V max values were calculated from Lineweaver-Burk graph. The apparent V max /K m value for O-dianisidine and H 2 O 2 were 400 and 5.0×105 Units/min/ mL respectively.

Peroxidase and Polyphenol Oxidase Activity in Moderate Resistant and Susceptible Vicia faba Induced by Aphis craccivora (Hemiptera: Aphididae) Infestation

“…Centrifugation was conducted after incubation at 12,000 rpm for 15 min at 4°C. Supernatant obtained after centrifugation was used directly for enzyme analysis ( Kavitha and Umesha 2008 , Kumar et al. 2011 ).…”