Atomic-Resolution Structural Dynamics in Crystalline Proteins from NMR and Molecular Simulation.

Area of Science:

• Biophysics
• Structural Biology
• Solid-state NMR Spectroscopy

Background:

• Solid-state NMR spectroscopy provides atomic-resolution insights into protein dynamics.
• It complements X-ray diffraction by studying motions across various timescales under similar conditions.
• Understanding protein dynamics in crystalline forms is crucial for biological function.

Purpose of the Study:

• To compare experimental solid-state NMR dynamic parameters with calculations from a molecular dynamics (MD) simulation.
• To assess the accuracy of standard methods for interpreting solid-state NMR relaxation data.
• To investigate protein dynamics within a crystalline lattice.

Main Methods:

• Experimental determination of dynamic parameters (spin relaxation, chemical shifts, dipolar couplings) using solid-state NMR.
• 200 ns molecular dynamics (MD) simulation of protein GB1 in its crystalline state.
• Comparison of experimental NMR data with MD simulation results.

Main Results:

• Experimental dynamic parameters were compared to values derived from a 200 ns MD simulation of crystalline protein GB1.
• The study tested common procedures for interpreting solid-state NMR relaxation data in terms of dynamic modes and timescales.
• The complexity of relaxation-active motion can lead to significant errors in dynamic amplitude estimations.

Conclusions:

• Solid-state NMR is a powerful tool for characterizing protein dynamics in crystals.
• MD simulations are valuable for validating and interpreting NMR relaxation data.
• Careful consideration of all motion components is essential for accurate quantification of protein dynamics.