Abstract: The present study was conducted to obtain high-purity catalase (CAT) from Chinese chives and explore some of its enzymological properties. Electrophoresis-purity CAT was obtained sequentially after homogenization, extraction, fractional ammonium sulfate precipitation, DEAE-Sepharose chromatographic separation and Superdex-200 gel filtration. In the process, a purification factor of 70.36, a recovery of 18.33% and a specific enzyme activity of 22064.57 U/mg were obtained. The enzyme exhibited a molecular weight of 241.76 kD and contained a 62.43 kD subunite. The optimum temperature and pH for this enzyme were 37 ℃ and 7.2, respectively. The CAT enzyme was stable under pH 5－9 and 25－40 ℃ conditions. Its Km was determined to be 46.93 mmol/L under optimum conditions. The enzyme activity could be strongly inhibited by methanol, ethanol, isopropanol, SDS, Cu2+, Ag+, and Fe2+.

Key words: Chinese chives, catalase, isolation and purification, characterization