Temperature as an Extra Dimension in Multidimensional Protein NMR Spectroscopy

Area of Science:

• Biophysics
• Structural Biology
• Biochemistry

Background:

• Nuclear Magnetic Resonance (NMR) spectroscopy is crucial for studying protein structure and dynamics in solution.
• Traditional multidimensional NMR experiments are time-consuming, with durations increasing exponentially with dimensions.
• Measuring temperature coefficients (TCs) requires repeating experiments under various conditions, further extending acquisition times.

Purpose of the Study:

• To develop a novel, time-efficient approach for measuring temperature coefficients (TCs) in biomolecular NMR spectroscopy.
• To enable the determination of TCs and their non-linearities from 3D spectra in less time than conventional single-spectrum acquisition.
• To provide a complete software package for data acquisition and processing for the new method.

Main Methods:

• Joint sampling of indirect evolution times and temperature during NMR data acquisition.
• Application of two complementary signal processing techniques: compressed sensing reconstruction and a variant of the Radon transform.
• Acquisition and analysis of temperature-swept 3D HNCO spectra for intrinsically disordered proteins.

Main Results:

• The proposed method allows TCs to be measured through 3D spectra more rapidly than conventional single-spectrum acquisition.
• Effective determination of TCs and their non-linearities was demonstrated for osteopontin and CD44 cytoplasmic tail.
• Non-linearities in TCs, indicative of compact states, were effectively identified.

Conclusions:

• The new NMR approach significantly accelerates the measurement of temperature coefficients, enhancing efficiency in protein studies.
• This method facilitates the effective characterization of protein dynamics and conformational states, including compact states indicated by non-linear TCs.
• The provided software package supports the implementation and application of this accelerated NMR technique.