Completing the Circuit: Direct-Observe (~13)C,(~15)N Double-Quantum Spectroscopy Permits Sequential Resonance Assignments near a Paramagnetic Center in Acireductone Dioxygenase

摘要

Nuclear magnetic resonance (NMR) spectroscopy is an indispensable tool for studying the structure and dynamics of biomol-ecules in solution. However, paramagnetic centers in proteins present difficulties for NMR in that electron-nuclear (EN) dipolar interactions efficiently relax nuclear spins near the paramagnetic center, short-circuiting coherence transfer between coupled spins and rendering most H-detected multidimensional NMR experiments useless for sequential resonance assignments in affected regions of the protein.