Structural features of the protophorphyrin-apomyoglobin complex. A proton NMR spectroscopy study
- The Pennsylvania State Univ., University Park (USA)
The structural properties of the complex formed by apomyoglobin and protoporphyrin IX (des-iron myoglobin) were studied to probe the influence of iron-to-histidine coordination on the native myoglobin fold and the heme binding site geometry. Standard two-dimensional proton nuclear magnetic resonance spectroscopy methods were applied to identify porphyrin and protein signals. A pronounced spectral resemblance between carbonmonoxymyoglobin and des-iron myogobin was noticed that could be exploited to assign a number of resonances by nuclear Overhauser spectroscopy. Protoporphyrin IX was determined to bind in the same orientation as the heme. Most residues in contact with the prosthetic group were found in the holomyoglobin conformation. Several tertiary structure features were also characterized near the protein termini. It was concluded that the protoporphyrin-apomyoglobin interactions are capable of organizing the binding site and the unfolded region of the apoprotein into the native holoprotein structure.
- OSTI ID:
- 5526406
- Journal Information:
- Biochemistry; (USA), Journal Name: Biochemistry; (USA) Vol. 29:50; ISSN 0006-2960; ISSN BICHA
- Country of Publication:
- United States
- Language:
- English
Similar Records
sup 1 H NMR study of the role of heme carboxylate side chains in modulating heme pocket structure and the mechanism of reconstitution of cytochrome b sub 5
Proton NMR study of the interaction of tin(IV) protoporphyrin IX monomers and dimers with apomyoglobin
Related Subjects
62 RADIOLOGY AND NUCLEAR MEDICINE
AMINO ACIDS
ANIMALS
AZOLES
BARYONS
CARBOXYLIC ACIDS
ELEMENTARY PARTICLES
FERMIONS
GEOMETRY
GLOBINS
HADRONS
HETEROCYCLIC ACIDS
HETEROCYCLIC COMPOUNDS
HISTIDINE
HORSES
IMIDAZOLES
MAGNETIC RESONANCE
MAMMALS
MATHEMATICS
MOLECULAR STRUCTURE
MYOGLOBIN
NUCLEAR MAGNETIC RESONANCE
NUCLEONS
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
OVERHAUSER EFFECT
PIGMENTS
PORPHYRINS
PROTEINS
PROTONS
PROTOPORPHYRINS
RESONANCE
VERTEBRATES