Characterization of partially purified catalase from camel (Camelus dromedarius) liver
The liver of camel has high level of catalase (32,225 units/g tissue) as commercially used bovine liver catalase. For the establishment of the enzyme, the rate of catalase activity was linearly increased with increase of the catalase concentration and incubation time. The procedure of partial purification of catalase from camel liver included preparation of crude extract, ammonium sulphate precipitation and chromatography on diethylaminoethyl cellulose (DEAE)-Sepharose. One peak catalase activity was obtained from the chromatography. The enzyme had optimum pH of 7.0. Camel liver catalase had broad optimum temperature between 25 and 40°C and was stable up to 25°C. The Km and Vmax values were found to be 22.7 mM H2O2/ml and 7.9 units/ml, respectively. All metal cations partially inhibited camel liver catalase with the exception of Hg2+ which had strong inhibitory effect, whereas 95% of its activity was lost at 1.0 mM. In conclusion, camel liver catalase can be used as an alternative commercial bovine liver catalase.
Key words: Camel, liver, catalase, purification, characterization.