Preparation of lysozyme molecularly imprinted polymers and purification of lysozyme from egg white

Molecular imprinting as a promising and facile separation technique has received much attention because of its high selectivity for target molecules. In this study, lysozyme molecularly imprinted polymers (Lys-MIPs) were successfully prepared by the entrapment method with lysozyme as the template molecule, acrylamide as the functional monomer and N,N-methylenebisacrylamide as the cross-linker. The removal of the template lysozyme from the molecularly imprinted polymers was investigated in detail by two methods. The synthesized Lys-MIPs were characterized by scanning electron microscopy and Fourier transform-infrared, and the adsorption capacity, selectivity and reproducibility of the Lys-MIPs were also evaluated. The maximum adsorption capacity reached 94.8 mg/g, which is twice that of nonmolecularly imprinted polymers, and satisfactory selectivity and reproducibility were achieved. Using the Lys-MIP column, lysozyme could be separated completely from egg white, with purity close to 100% and mass recovery of 98.2%. This illustrated that the synthesized Lys-MIPs had high specific recognition and selectivity to the template lysozyme when they were applied to a mixture of protein standards and a real sample.