Lysozyme Complexes for the Synthesis of Functionalized Biomaterials To Understand Protein-Protein Interactions and Their Biological Applications

Interactions between the components of lysozyme/cytochrome c (lysozyme/Cyt,c) and lysozyme/zein protein mixtures were determined by following the in vitro synthesis of gold (Au) nanoparticles (NPs). Both UVvisible and fluorescence studies were employed to monitor the interactions and simultaneous synthesis of protein coated NPs. Protein coated NPs were characterized by gel electrophoresis and TEM studies. Lysozyme/Cyt,c complex coated NPs showed remarkable pH responsive behavior due to their amphiphilic nature, while lysozyme/zein complex coated NPs were not pH sensitive because of the predominantly hydrophobic nature. The results were further supported by molecular dynamics studies (MD) of proteinprotein interactions and interactions of protein with the gold surface. Molecular simulations helped us to identify the amino acids that drove such interactions. Biological applications of protein coated NPs were determined from hemolytic and antimicrobial studies to demonstrate their potential in pharmaceutical and food industries. The results clearly differentiated between the greater applicability of predominantly amphiphilic lysozyme/Cyt,c complex coated NPs in comparison to predominantly hydrophobic lysozyme/zein complex coated NPs.