Dynamics and Thermodynamics Study of the Adsorption of Lysozyme to 2D SnSe Nanoflake Surfaces with Associated Unfolding

Abstract

AbstractIn this work, we explore the interaction as well as corona formation and interfacial phenomena of lysozyme (LYZ) and 2D SnSe nanoflake. The optical results indicate formation of ground state complex with an apparent association constant of 1.5 × 103 (mol)−1. The dynamics of the in situ interaction exhibited surface reorganization (t2 = 73.5 min) and unfolding, which were more prominent than binding (t1 = 3 min) for tryptophan residues of LYZ. The formations of soft and hard corona of the LYZ structure were clearly observed from HRTEM. The emission quenching exhibited tertiary deformation of the LYZ structure with positive cooperative binding (n > 1) and dynamics of quenching followed the sigmoidal Boltzmann nature of the energy transfer process. The ultrafast lifetime of the bioconjugate varied from 1.9–1.35 ns with a maximum 63% energy transfer efficiency within 300 min of the corona evolution. The decrement of α helix (58.87%–21.78%) and increment of β sheet (5.27%–23.98%) were observed after interaction, with the conversion of large amount of α helix into β sheet. The ITC results showed that the injection heat results followed two‐site binding model, and the exothermic binding was dominate over the interaction. The second phase binding is driven by larger positive entropy, where the first binding site has a stronger association.