关键词: β-1,3(4)-葡聚糖酶, 同源建模, 共价固定化

Abstract: The three-dimensional structure of β-1,3(4)-glucanase from Paecilomyces sp. FLH30 was constructed by means of homology modeling using the crystal structure of endo-β-1,3(4)-glucanase from Phanerochaete chrysosporium as a template, and its active site and side chains of surface amino acid residues were analyzed. Sepabeads EC-HA as a carrier of amino groups was used for the covalent immobilization of this enzyme and immobilization conditions were optimized. Meanwhile, enzymatic characteristics of free and immobilized β-1,3(4)-glucanase were compared. The best immobilization results were obtained under the conditions: enzyme/carrier mass ratio1.2:1, temperature 40—45 ℃, and immobilization time 8 h. Under these conditions, the protein binding rate was 91.7% and the activity recovery was 87.6%. The optimum temperature, thermal stability, pH stability and operational stability of immobilized glucanase were all improved when compared to free glucanase.

Key words: β-1,3(4)-glucanase, homology modeling, covalent immobilization