Structural evolution of protein-biofilms: Simulations and Experiments

TL;DR

This study combines experiments and simulations to explore how van der Waals forces and protein conformational changes influence biofilm formation, providing new insights into protein adsorption mechanisms.

Contribution

It introduces a combined experimental and Monte Carlo simulation approach to analyze protein adsorption, emphasizing the role of van der Waals forces and conformational dynamics.

Findings

Van der Waals forces significantly affect protein adsorption.

Conformational stability influences adsorption kinetics.

Simulations match experimental site distributions.

Abstract

The control of biofilm formation is a challenging goal that has not been reached yet in many aspects. One is the role of van der Waals forces and another the importance of mutual interactions between the adsorbing and the adsorbed biomolecules ('critical crowding'). Here, a combined exeperimental and theoretical approach is presented that fundamentally probes both aspects. On three model proteins, lysozyme, {\alpha}-amylase and bovine serum albumin (BSA), the adsorption kinetics is studied. Composite substrates are used enabling a separation of the short- and the long-range forces. Though usually neglected, experimental evidence is given for the influence of van der Waals forces on the protein adsorption as revealed by in situ ellipsometry. The three proteins were chosen for their different conformational stability in order to investigate the influence of conformational changes on the adsorption kinetics. Monte Carlo simulations are used to develop a model for these experimental results by assuming an internal degree of freedom to represent conformational changes. The simulations also provide data on the distribution of adsorption sites. By in situ atomic force microscopy we can also test this distribution experimentally which opens the possibility to e.g. investigate the interactions between adsorbed proteins.