Abstract:

Electrophoresis-purity catalase (CAT) was obtained from freshly sprouted soybean (Glycine max) by the
sequential steps of homogenization, buffer solution extraction, ammonium sulfate precipitation, DEAE-Sepharose ion
exchange chromatography and Superdex-200 gel filtration chromatography. The purified enzyme had a specific activity of
26 322.43 U/mg, with a 30.92% activity recovery and a 293.09-fold purification. The molecular mass of the CAT enzyme
comprising a 57.42 kD subunit was 234.9 kD. Its optimum pH and temperature were 7.2 and 30 ℃, respectively. This
enzyme was stable at pH 4.0–10.6 and at 25–35 ℃. Its Km towards H2O2 was 31.82 mmol/L. The enzyme activity was
strongly inhibited by sodium dodecyl sulfate (SDS), oxalic, Ag+ and Cu2+, but was activated by low concentration of Pb2+.

Key words: soybean, catalase, isolation and purification, characterization