Purification and Some Kinetic Properties of Catalase from Parsley (Petroselinum hortense Hoffm., Apiaceae) Leaves

Abstract

In this study, catalase (CAT: EC 1.11.1.6) was purified from parsley (Petroselinum hortense) leaves; analysis of the kinetic behavior and some properties of the enzyme were investigated.

The purification consisted of three steps, including preparation of homogenate, ammonium sulfate fractionation, and fractionation by DEAE‐Sephadex A50 ion exchange chromatography.

The enzyme was obtained with a yield of 9.5% and had a specific activity of 1126 U (mg proteins)⁻¹. The overall purification was about 5.83‐fold. A temperature of 4°C was maintained during the purification process. Enzyme activity was spectrophotometrically measured at 240 nm.

In order to control the purification of the enzyme, SDS‐polyacrylamide gel electrophoresis was carried out in 4% and 10% acryl amide for stacking and running gel, respectively. SDS‐polyacrylamide gel electrophoresis showed a single band for the enzyme. The molecular weight was found to be 183.29 kDa by Sephadex G‐200 gel filtration chromatography. The stable pH, optimum pH, and ionic strength were determined for phosphate and Tris‐HCl buffer systems. In addition, K_M and V_max values for H₂O₂, at optimum pH and 25°C, were determined by means of Lineweaver‐Burk plots.

Keywords:

• Catalase
• Parsley
• Properties
• Purification