Immobilization of a Thermostable Inorganic Pyrophosphatase from the Archaeon Pyrococcus furiosus onto Amino-Functionalized Silica Beads

摘要

This study focuses on the preparation and application of a recombinant thermophilic inorganic pyrophosphatase from the archaeon Pyrococcus furiosus on amino-functionalized silica beads. The amino-functionalized silica beads were prepared by coating with 3-aminopropyltriethoxysilane by silanization. The thermostable inorganic pyrophosphatase was rapidly and successfully immobilized onto the amino-functionalized silica beads with glutaraldehyde as a coupling agent (within 12 min, >95.4% protein was immobilized onto the support). The results show that the protein could be immobilized efficiently, with up to 1 mg of protein/g of support with 92.9% activity. Compared with the free enzyme, the immobilized enzyme displayed a high activity toward inorganic pyrophosphate, less sensitivity toward the pH, and increased thermal stability. The immobilized enzyme retained 56.9% of its initial activity after hydrolysis of the inorganic pyrophosphate after 12 consecutive cycles (total=330 min) at high temperature; this indicated a high protein stability suitable for practical applications.