Immobilization of lactoperoxidase on graphene oxide nanosheets with improved activity and stability

Abstract

ObjectivesThe purpose of this study was to develop a facile and efficient method to enhance the stability and activity of lactoperoxidase (LPO) by using its immobilization on graphene oxide nanosheets (GO-NS).MethodsFollowing the LPO purification from bovine whey, it was immobilized onto functionalized GO-NS using glutaraldehyde as cross-linker. Kinetic properties and stability of free and immobilized LPO were investigated.ResultsLPO was purified 59.13 fold with a specific activity of 5.78U/mg protein. The successful immobilization of LPO on functionalized GO-NS was confirmed by using dynamic light scattering (DLS) and Fourier transform infrared spectroscopy (FT-IR). The overall results showed that the stability of the immobilized LPO was considerably improved compared to free LPO. Apparent K-m and V-max of LPO also indicated that the immobilized enzyme had greater affinity to the substrate than the native enzyme.ConclusionsGraphene oxide nanosheets are effective means for immobilization of LPO.