1H NMR resonance assignments in a paramagnetic heme protein by two-dimensional spectroscopy: heme resonances in equine met-azido myoglobin.
Specific heme protons for the majority of resonances in the downfield resolved region of equine met-azido myoglobin have been assigned using solely the two-dimensional 1H NMR experiments NOESY and COSY. Metazido myoglobin provides a useful test case for the applicability of these techniques to paramagnetic proteins for the following reasons. First met-azido myoglobin is a mixed spin-state protein, with significantly shorter relaxation times and broadened lines relative to pure low-spin systems (eg., met-cyano myoglobin). Second, met-azido hemoglobin and met-azido myoglobin are important as models for the physiological forms of hemoglobin. Third, a few sperm whale met-azido myoglobin resonances have been previously assigned, which permits a comparison of assignments for these similar proteins, and a check of the method presented here.
Peyton
D H
DH
Chemistry Department, Portland State University, Oregon 97207-0751.
D000818:Animals; D001386:Azides; D006420:Hemeproteins / Q000737:chemistry*; D006736:Horses; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008786:Metmyoglobin / Q000737:chemistry*
D001386:Azides; D006420:Hemeproteins; D008786:Metmyoglobin