Conformational dynamics in peptides and proteins on the nanoseconds to microseconds time scale

• Applicant: Professor Dr. Thomas Kiefhaber
• Subject Area: Biophysics
• Term: from 2016 to 2022
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 320671684

Proteins exist in an equilibrium between different conformational states. The transitions between these states are closely connected to their biological function. In this project we aim to investigate conformational dynamics in peptides and proteins on the nanoseconds to microseconds time scale. Dynamics on this time scale are experimentally difficult to characterize and are thus only poorly understood. We will use experimental biophysical methods to study conformational equilibria in peptides and proteins in order to determine their structural, thermodynamic and dynamic properties. In the proposed experiments we will couple fast triplet-triplet-energy-transfer (TTET) to conformational equilibria to obtain information on equilibrium fluctuations on the nanoseconds to microseconds time scale. This method is sensitive for local and global unfolding reactions and is able to discriminate between different conformational substates, even when they are structurally very similar. The experiments will yield both thermodynamic and dynamic information on the equilibria. In addition, we will conduct hydrogen/deuterium (H/D) exchange and high-pressure NMR experiments, which will give detailed structural information on the different conformational states. We will study the dynamics of alpha-helical und beta-hairpin peptides as well as different variants of the actin-binding villin headpiece domain (HP35, HP45 and HP67). In parallel, the group of Prof. Lillian Chong will study the same model systems with molecular dynamics (MD) simulations with explicit water. The combination of results from our experimental studies and the all-atom MD simulations will give a detailed structural and dynamic picture of conformational fluctuations in proteins and peptides.

• DFG Programme: Research Grants