Stabilization of whey lactoperoxidase using betaine: Spectroscopic and computational approaches

Abstract

Lactoperoxidase (LPO) is a peroxidase with antibacterial properties. In the present study, lactoperoxidase was isolated and stabilized using betaine. Betaine enhanced optimal pH, enzyme native activity, and enzyme residual activity. Betaine reduced LPO fluorescence using a static quenching mechanism. The results showed that hydrogen bonding and van der Waals interactions were responsible for ligand-LPO binding. The negative values of Gibes free energy indicated that the binding of betaine to the LPO was spontaneous. The circular dichroism studies showed that the secondary and tertiary structures of the enzyme were altered in the presence of betaine. The results of thermal stability studies presented that betaine increased the enzyme Tm. Furthermore, the docking and MD investigations demonstrated that betaine might spontaneously attach to the LPO with hydrogen bonding and van der Waals interactions. Finally, betaine might be employed as an additive to stabilize lactoperoxidase for usage in the food and pharmaceutical industries.