Collective Molecular Dynamics in Proteins and Membranes

TL;DR

This paper reviews how inelastic neutron scattering helps understand the complex molecular dynamics in biological membranes and embedded proteins, shedding light on their elastic properties and interactions at nanometer scales.

Contribution

It provides a comprehensive overview of experimental findings using inelastic neutron scattering to analyze membrane and protein dynamics, highlighting recent advances and challenges.

Findings

Correlated molecular motions are crucial for membrane and protein function.

Inelastic neutron scattering effectively probes nanometer-scale dynamics.

Membrane composition influences protein interactions and elasticity.

Abstract

The understanding of dynamics and functioning of biological membranes and in particular of membrane embedded proteins is one of the most fundamental problems and challenges in modern biology and biophysics. In particular the impact of membrane composition and properties and of structure and dynamics of the surrounding hydration water on protein function is an upcoming hot topic, which can be addressed by modern experimental and computational techniques. Correlated molecular motions might play a crucial role for the understanding of, for instance, transport processes and elastic properties, and might be relevant for protein function. Experimentally that involves determining dispersion relations for the different molecular components, i.e., the length scale dependent excitation frequencies and relaxation rates. Only very few experimental techniques can access dynamical properties in biological materials on the nanometer scale, and resolve dynamics of lipid molecules, hydration water molecules and proteins and the interaction between them. In this context, inelastic neutron scattering turned out to be a very powerful tool to study dynamics and interactions in biomolecular materials up to relevant nanosecond time scales and down to the nanometer length scale. We review and discuss inelastic neutron scattering experiments to study membrane elasticity and protein-protein interactions of membrane embedded proteins.