Backbone assignment of perdeuterated proteins using long-range H/C-dipolar transfers

Area of Science:

• Biochemistry
• Structural Biology
• Spectroscopy

Background:

• Solid-state NMR of perdeuterated proteins yields high-quality spectra.
• Deuteration enhances resolution and coherence lifetimes, enabling advanced techniques.
• Fibrillar and membrane proteins exhibit shorter transverse relaxation times than micro-crystalline proteins.

Purpose of the Study:

• To develop a novel strategy for sequential resonance assignment in perdeuterated proteins.
• To overcome limitations imposed by short transverse relaxation times in challenging protein samples.
• To enable detailed structural analysis of fibrillar and membrane-embedded proteins using NMR.

Main Methods:

• Utilized solid-state nuclear magnetic resonance (NMR) spectroscopy.
• Employed perdeuterated protein samples.
• Developed and applied a novel approach based on long-range (1)H/(13)C Cross Polarization transfers for sequential assignment.

Main Results:

• Achieved H/N-separated correlations revealing C(α), C(β), and CO chemical shifts.
• Successfully connected intra- and interresidual contacts, linking adjacent residues.
• Demonstrated independence from transverse relaxation times, a key advancement for challenging samples.

Conclusions:

• The proposed cross-polarization strategy enables robust sequential assignment of perdeuterated proteins.
• This method overcomes relaxation limitations in fibrillar and membrane protein studies.
• Facilitates detailed structural characterization of complex protein systems via solid-state NMR.