Resumo

CASTRO, A.; GONZALEZ, I.; TZOMPANTZI, F.  e  VINIEGRA-GONZALEZ, G.. Influence of the type of support and immobilization on the activity and stability of laccase enzyme (Trametes versicolor). Rev. Mex. Ing. Quím [online]. 2013, vol.12, n.2, pp.241-255. ISSN 1665-2738.

This work presents a comparative study of the influence of the nature of the substrate and the immobilization mechanism on laccase enzyme activity and stability. The supports employed were: hydrotalcite-like particles (ZnAl₂), amorphous silica crystals, and glassy carbon surface. Two immobilization mechanisms were applied: one physical, by adsorption, and the other chemical, with two versions of covalent bonding. In the first, using silanes and glutaraldehyde (GA), in the second, thiols were used as anchoring reagents. Hydrotalcite and silica supports were characterized before and after immobilizing the enzyme by X-ray diffraction analysis (XRD), while in the case of glassy carbon supports electrochemical characterization was performed. The catalytic properties K_m and K_cat/K_m of every enzymatic system were evaluated in a complementary fashion, as well as the free enzyme. The kinetic characterizations were done using ABTS (ammonium 2,2' azino-bis-(3 -ethylbenzothiazoline-6-sulfonate acid)), as a reagent typical of laccase in 0.1 M acetate buffer solution pH 3.7. Efficiency of the enzyme adsorbed on each support it was demonstrated that the method of immobilization is decisive in the catalysis. Greater efficiency was observed in the system that employed glassy carbon with either immobilization mechanism and these results are analogous with the tree enzyme.

Palavras-chave : laccase; immobilization; thiol; glassy carbon; hydrotalcite.