Assessing the Suitability of using Plant Latex as Immobilization Support for Horseradish Peroxidase

Horseradish peroxidase was immobilized onto latex from three different plants viz. Calotropis procera, Euphorbia royleana and Alstonia scholaris with 0.51 ± 0.01, 0.37 ± 0.01, 0.46 ± 0.01 mg/cm2 conjugation yield and 62.07 ± 0.85, 66.1 ± 0.85, 71.24 ± 0.80 % retention of specific activity respectively. The support, before and after addition of peroxidase was characterized using scanning electron microscopy (SEM) and Fourier transmission infra-red spectroscopy (FTIR). Optimum pH, optimum temperature and changes in kinetic parameters (Ea, Km and Vmax) for immobilized peroxidases were studied and found to differ from that of free peroxidase. Alstonia scholaris latex was most effective in stabilizing the structure of peroxidase during storage at 4°C, whereas thermal stability and reusability of peroxidase was better on Calotropis procera latex. Analytical use of Calotropis procera latex bound peroxidase for determination of phenolic content of fruit juices has also been demonstrated.