Immobilization of Laccase Through Inorganic-Protein Hybrids Using Various Metal Ions

In this study, the inorganic-protein hybrid strategy was employed for immobilization of laccase from Rhus vernicifera ( Rv lac) using various metals calcium, cobalt, copper, and zinc (Zn). The efficient synthesis of hybrids for Rv lac immobilization was noted at 4 °C for incubation of 24 h. Among these hybrids, the maximum encapsulation yields (EY) of 90.1% and relative activity (RA) of 225% to free enzyme were recorded for Zn and Rv lac based inorganic-protein hybrids as Zn 3 (PO 4 ) 2 - Rv lac. The upper optimum pH, and temperature values were observed of 4.0, and 45 °C after immobilization as compared to 3.5, and 40 °C for the free enzyme, respectively. After encapsulation, Rv lac showed a significant improvement up to 11.4-fold in pH and 5.7-fold in temperature the activity profiles. Free enzyme completely lost its activity at 60 °C after 2 h of incubation, whereas Zn 3 (PO 4 ) 2 - Rv lac retained its residual activity of 56.7% under similar conditions. After ten cycles of reusability, Zn 3 (PO 4 ) 2 - Rv lac possessed high residual activity of 90.8%. This study showed that the variation in the metal ions for immobilization of Rv lac as inorganic-protein hybrids significantly altered EY and RA. Also, Zn 3 (PO 4 ) 2 - Rv lac proved more efficient as compared to free laccase that can be beneficially employed for biotechnological applications.