Abstract:

Electrophoretically pure lysozyme from bovine kidney was obtained through homogenization, buffer extraction,
butanol degreasing, ammonium sulfate fractionation precipitation, CM-Sepharose ion-exchange chromatography and
Superdex-200 gel filtration chromatography. Results showed that the specific activity of the purified lysozyme was
15 145.63 U/mg with a recovery rate of 29.13% and the enzyme was purified 231.05 folds. The molecular weight of the
lysozyme was approximately 12.66 kD, which consisted of a single subunit. The optimum temperature of the enzyme was
65 ℃ and it was stable at temperatures below 65 ℃; the optimum pH of this enzyme was 9.0 and it was stable in the range
of pH 3.0–9.0. Its Km towards micrococcus lysodeikticus was 0.399 μg/mL. The enzyme activity was enhanced by methanol,
ethanol, isopropanol and KSCN, and inhibited by SDS, Pb2+, and Ag+.

Key words: bovine kidney, lysozyme, isolation and purification, enzymatic properties