Proton NMR assignments of heme contracts and catalytically implicated amino acids in cyanide-ligated cytochrome c peroxidase determined from one- and two-dimensional nuclear Overhauser effects

Journal Article · Tue May 07 00:00:00 EDT 1991 · Biochemistry; (United States)

DOI:https://doi.org/10.1021/bi00232a005· OSTI ID:5594898

Satterlee, J D ^[1]; Erman, J E ^[2]

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1. Washington State Univ., Pullman (USA)
2. Northern Illinois Univ., DeKalb (USA)

Proton NMR assignments of the heme pocket and catalytically relevant amino acid protons have been accomplished for cyanide-ligated yeast cytochrome c peroxidase. This form of the protein, while not enzymatically active itself, is the best model available (that displays a resolvable proton NMR spectrum) for the six-coordinate low-spin active intermediates, compounds I and II. The assignments were made with a combination of one- and two-dimensional nuclear Overhauser effect methods and demonstrate the utility of NOESY experiments for paramagnetic proteins of relatively large size (M{sub r} 34,000). Assignments of both isotope exchangeable and nonexchangeable proton resonances were obtained by using enzyme preparations in both 90% H{sub 2}O/10% D{sub 2}O and, separately, in 99.9% D{sub 2}O solvent systems. Complete resonance assignments have been achieved for the proximal histidine, His-175, and His-52, which is a member of the catalytic triad on the distal side of the heme. In addition, partial assignments are reported for Trp-51 and Arg-48, catalytically important residues, both on the distal side. Aside from His-175, partial assignments for amino acids on the proximal side of the heme are proposed for the alanines at primary sequence positions 174 and 176 and for Thr-180 and Leu-232.

• OSTI ID: 5594898
• Journal Information: Biochemistry; (United States), Vol. 30:18; ISSN 0006-2960
• Country of Publication: United States
• Language: English

Related Subjects

62 RADIOLOGY AND NUCLEAR MEDICINE
AMINO ACIDS
NUCLEAR MAGNETIC RESONANCE
HEME
PEROXIDASES
MOLECULAR STRUCTURE
ARGININE
CYTOCHROME OXIDASE
CYTOCHROMES
HEAVY WATER
HISTIDINE
MOLECULAR WEIGHT
OVERHAUSER EFFECT
PROTONS
TRYPTOPHAN
YEASTS
AROMATICS
AZAARENES
AZOLES
BARYONS
CARBOXYLIC ACIDS
ELEMENTARY PARTICLES
ENZYMES
EUMYCOTA
FERMIONS
FUNGI
HADRONS
HAEM DEHYDROGENASES
HETEROCYCLIC ACIDS
HETEROCYCLIC COMPOUNDS
HYDROGEN COMPOUNDS
IMIDAZOLES
INDOLES
MAGNETIC RESONANCE
MICROORGANISMS
NUCLEONS
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
OXIDOREDUCTASES
OXYGEN COMPOUNDS
PIGMENTS
PLANTS
PORPHYRINS
PROTEINS
PYRROLES
RESONANCE
WATER
550601* - Medicine- Unsealed Radionuclides in Diagnostics