Thermodynamic, kinetic and conformational analysis of proteins diffusion-sorption on a solid surface

Area of Science:

• Physical Chemistry
• Biophysics
• Surface Science

Background:

• Proteins undergo conformational changes when interacting with solid surfaces.
• Diffusion, adsorption-desorption, and reaction kinetics are crucial in these surface interactions.
• Understanding these processes is vital for applications involving protein-surface interactions.

Purpose of the Study:

• To develop a thermodynamic and kinetic framework for analyzing protein conformational changes at solid-liquid interfaces.
• To investigate the influence of factors like protein flexibility, surface energy, and site interactions on conformational dynamics.
• To model the steady-state behavior of adsorbed protein monolayers.

Main Methods:

• Thermodynamic and kinetic analytical development.
• Modeling of protein conformational changes (folding-misfolding-unfolding) on solid surfaces.
• Analysis of diffusion, adsorption, and reaction steps.

Main Results:

• Identified three distinct steady-state situations based on rate-determining steps: reaction rate, diffusion/sorption, or mixed control.
• Demonstrated the theory using examples like Ribonuclease (RNase) and Staphylococcal Nuclease (SNase) conformational changes.
• Highlighted the impact of non-ideality, protein flexibility, surface free energy, and reactive sites on conformational rates.

Conclusions:

• The developed theory provides a framework for understanding protein behavior at surfaces.
• The study links theoretical predictions to experimental observations in protein diffusion-sorption-reaction processes.
• This work contributes to the fundamental understanding of protein-surface interactions, relevant to various scientific investigations.