Enhancement of internal motions of lysozyme through interaction with gold nanoclusters and its optical imaging

Abstract

Understanding the interaction of gold nanoclusters with proteins has important ramifications in various fields. We present a study of the interaction between gold nanoclusters and lysozyme investigated using classical molecular dynamics and center-of-mass pulling simulations. The results reveal that the gold nanoclusters induce significant structural changes in lysozyme. Because the internal motions of lysozyme are related to its function, the changes in these internal motions have been quantified using principal component analysis of the molecular dynamics trajectories. The internal motions of lysozyme that are important for its function have been altered because of the interaction with the gold nanocluster. We have also explored how these induced changes in the lysozyme structure affect specific optical properties of the gold nanocluster using the complex polarization propagator method within the time-dependent density functional theory framework, which is of relevance for studies of the optical imaging of lysozyme using gold nanoclusters as molecular probes.