Determination of kinetic parameters of catalase of different origin immobilized on water-insoluble glucan synthesized by recombinant glycosyltransferase URE13-300

. The kinetic constants determined for three enzymes of different origins – fungal, bacterial, and mammal, have been compared in the process of hydrogen peroxide disproportionation as a model reaction. In order to stabilize the enzyme, it has been immobilized on waterinsoluble glucan whilst the studied process has been carried out in both the absence and the presence of low molecular weight aliphatic alcohols over a wide range of concentrations. In this study, purified catalases originating from the fungus Penicilium chrysogenum, bacteria Micrococcus lysodeikticus, and mammalian from the bovine liver, have been used. Their activities were determined by means of a spectrophotometric method, following the decay of the absorbance at 240 nm at a constant temperature, over the temperature range from 0 to 25°C. The catalytic processes were performed in the presence of methyl and ethyl alcohols in concentrations from 1% to 10%. For catalase immobilization, the water-insoluble glucan URE13-300 was used as a carrier when determining heterogeneous catalytic enzyme activity. The best and most stable was found to be the enzyme from P. chrysogenum, both immobilized and in the native state. It was found that the immobilized enzyme retains its activity over the temperature range – from 0 to 25°C. Its apparent kinetic constants were calculated to be: Km =109.4 mM and Vmax =14.42 μmol l-1 s -1 . Preservation of the catalytic activity above 90% of the initial one was found in the presence of ethanol and methanol at concentrations not exceeding 3%.