Application of Immobilized α-Amylase onto Functionalized Calix[4]arene for the Degradation of Starch

In the present study, water soluble 5,17-bis[(N-methylglucamine)methyl]-25,26,27,28-tetrahydroxycalix[4]arene (3, as a highly efficient excipient material) was synthesized to immobilize α-amylase first time using the N-methylglucamine functionalities for excipient-enzyme complex formation at its para-positions. The excipient-α-amylase complex (4) was used for the starch degradation. The optimum apparent activity of 4 was determined at variable conditions such as the effect of pH (7.0), temperature (25 °C) and initial concentration of enzyme (15 μL). Under such optimized parameters, the maximum 71% yield of enzyme was immobilized onto the functionalized calix[4]arene material (3). The catalytic properties of 4 were determined by comparing with free α-amylase. The complex 4 revealed high stability under sever conditions, i.e. high temperature and offers multiple reuses with little loss in enzyme activity due to higher α-amylase concentration has been protected by complex. In addition, the enzyme activity and the excipient-α-amylase complex were found to have extra characteristics as compared to the free α-amylase for starch hydrolysis with respect to its stability and reusability. These advantageous characteristics and low cost of material from which calixarene derivative was prepared, making it economically viable for starch degradation on industrial scale.