Synthesis And Complexation Of A New Caffeine Based Surface Active Ionic Liquid With Lysozyme In Aqueous Medium: Physicochemical, Computational And Antimicrobial Studies

A new biodegradable, caffeine and dioctyl sulfosucci nate (AOT) based surface active ionic liquid (SAIL) has been synthesized and investigated for its complexation with lysozyme (LYZ) to develop antimicrobial SAIL-LYZ colloidal complexes with enhanced activity. Interfacial properties of the formed SAIL-LYZ colloidal complexes in the aqueous medium have been investigated using tensiometly, while the complexation in bulk has been monitored with dynamic light scattering, zeta-potential and turbidity measurements. Fluorescence and circular didiroism studies have been employed to gain insight about the structural modification of LYZ on complexation with SAIL. Isothermal titration calorimetry has been employed to monitor the thermodynamics of complexation of SAIL with LYZ, whereas the binding behavior of SAIL with LYZ has been investigated using molecular docking. Further, the antimicrobial activity of SAIL-LYZ complexes has been investigated against Gram-positive and Gram-negative bacteria. Fascinatingly, depending upon the concentration of SAIL SAIL-LYZ colloidal complexes have been found to exhibit enhanced antimicrobial activity as compared to control and the known antibiotics. It is anticipated that the present study of new colloidal complexes of SAIL with enzymes would be helpful in various biomedical applications. (C) 2020 Elsevier B.V. All rights reserved.