Abstract:

Electrophoresis-purity catalase from fresh garlic seedlings was obtained through homogenization, buffer solution
extraction, ammonium sulfate precipitation, DEAE-Sepharose ion exchange chromatography and Superdex-200 gel filtration
chromatography. The specific activity of purified CAT was 25975.36 U/mg with a recovery of 40.05% and a purification
factor of 125.97. The molecular and subunit molecular weight of this enzyme was 234.93 kD and 59.16 kD, respectively.
It was relatively stable in the range of 25—45 ℃ and pH 5.0—10.0 Its optimum temperature and pH were 45 ℃ and 7.2,
respectively. Furthermore, its Km was 38.2 mmol/L under the optimum conditions. Its activity was inhibited by methanol,
ethanol, isopropanol, SDS and KSCN as well as some metal ions such as Ag+, Cu2+, Mn2+, Co2+, Cd2+, Zn2+, Ca2+, Mg2+ and
Ba2+, but was activated by Li+ and Pb2+ as well as low concentration of K+.

Key words: garlic seedlings, catalase, isolation and purification, characterization