Protein elasticity probed with two synchrotron-based techniques.

Area of Science:

• Biophysics
• Protein dynamics
• Materials science

Background:

• Protein compressibility is crucial for understanding protein dynamics, structure, and function.
• Existing methods for measuring protein compressibility yield variable results and have limitations.

Purpose of the Study:

• To apply nuclear resonance vibrational spectroscopy and inelastic X-ray scattering to measure the adiabatic compressibility of cytochrome c.
• To introduce a novel, global method for material compressibility measurement.

Main Methods:

• Utilized synchrotron-based nuclear resonance vibrational spectroscopy (NRVS) and inelastic X-ray scattering (IXS).
• Measured adiabatic compressibility of cytochrome c under ambient pressure.
• Employed a novel approach that probes the protein globally and does not require separation of protein and solvent contributions.

Main Results:

• Successfully measured the adiabatic compressibility of cytochrome c using NRVS and IXS.
• Demonstrated that protein compressibility is largely independent of temperature when compared with molecular dynamics predictions.
• This marks the first report of compressibility measured using this specific synchrotron-based technique.

Conclusions:

• The novel synchrotron-based method provides a global, native-state measurement of protein compressibility.
• The compressibility of cytochrome c is found to be nearly constant across temperatures.
• This technique holds potential for application to a wider range of materials beyond proteins.