(37d) Protein Interfacial Behavior Studied with Multiscale Simulations

Mohammadreza Samieegohar, Tao Wei,

Dan F. Smith Department of Chemical Engineering, Lamar University, Texas, 77710.

Understanding of the protein adsorption dynamic process plays a prominent role in chemical, materials, biotechnologies and medical industries. In this work, protein interfacial dynamic behavior (i.e., adsorption, aggregation and surface mobility) on Au (111) surface in a micro-channel has been investigated with a multi-scale simulation approach, which consists of atomistic Molecular Dynamic (MD) simulation, free energy computation, Langevin Dynamics (LD) simulation with coarse-gained model and computational fluid dynamics (CFD). Atomistic simulation demonstrates that the gold surface has strong attraction to lysozyme proteins mainly due to gold surfaceâ??s dehydration. The protein-surface desorption free energy is up to 150 kJ/mol. LD simulation reveals that protein-protein interaction and Brownian dynamic motion are the main driving forces for protein desorption from the attractive gold surface, and desorption time scale can be up to microseconds. Protein molecules tightly adsorbed onto the surface in the first layer display large surface mobility affected by shear stress. CFD demonstrates protein adsorption different kinetics regions correlated with protein-surface interactions, bulk fluid velocity, bulk concentration and microchannel dimensions.