Translational diffusion of unfolded and intrinsically disordered proteins

Area of Science:

• Biophysics
• Protein Science
• Nuclear Magnetic Resonance (NMR) Spectroscopy

Background:

• Translational diffusion coefficient is inversely proportional to molecular size.
• Self-diffusion coefficient measurements determine effective hydrodynamic radii.
• Useful for assessing protein compactness and conformational changes.

Purpose of the Study:

• To review translational diffusion of disordered proteins in dilute and crowded solutions.
• To highlight the utility of pulsed-field gradient NMR technique.
• To draw analogies with well-structured proteins and synthetic polymers.

Main Methods:

• Pulsed-field gradient NMR technique.
• Measurement of translational diffusion coefficients.
• Analysis of hydrodynamic radii.

Main Results:

• Translational diffusion measurements provide insights into protein size and compactness.
• Effective hydrodynamic radii can be estimated for disordered proteins.
• Changes in protein compactness can be monitored by varying environmental parameters.

Conclusions:

• Translational diffusion is a valuable tool for studying protein conformations, particularly disordered proteins.
• Pulsed-field gradient NMR is a key technique for these investigations.
• Analogies can be drawn between disordered proteins, globular proteins, and synthetic polymers.