Double- and zero-quantum NMR relaxation dispersion experiments sampling millisecond time scale dynamics in proteins

Area of Science:

• Biochemistry
• Structural Biology
• Nuclear Magnetic Resonance (NMR) Spectroscopy

Background:

• Proteins undergo dynamic processes on millisecond timescales, crucial for their function.
• Existing NMR methods for studying protein dynamics have limitations in quantitative analysis.
• Distinguishing between simple and complex exchange processes in proteins is challenging.

Purpose of the Study:

• To develop novel TROSY-based NMR relaxation dispersion experiments.
• To study millisecond dynamic processes in proteins with enhanced quantitative accuracy.
• To improve the characterization of protein conformational exchange.

Main Methods:

• Utilized Transverse Relaxation-Optimized Spectroscopy (TROSY)-based NMR.
• Measured the decay of double- and zero-quantum (1H)-(15N) coherences under varying radio frequency (rf) fields.
• Developed a TROSY-based pulse scheme for amide (1H) single-quantum magnetization relaxation measurements.

Main Results:

• Presented new NMR experiments for studying millisecond protein dynamics.
• Demonstrated that combining data from multiple coherences provides a more quantitative dynamic picture.
• Successfully applied the methodology to a Fyn SH3 domain mutant exhibiting folded-unfolded state exchange.

Conclusions:

• The developed TROSY-based NMR experiments offer a complementary approach to existing methods.
• The new methodology enhances the ability to distinguish between different types of protein exchange processes.
• This approach provides a more comprehensive understanding of protein dynamics and conformational changes.