Characterization of hydrophobic cores in apomyoglobin: a proton NMR spectroscopy study.
A proton nuclear magnetic resonance spectroscopic study of horse apomyoglobin was undertaken in order to define the regions of myoglobin that are and that are not structurally affected by the binding of the prosthetic group. It was found that, in spite of the poor spectral resolution, a number of spin systems could be identified by using standard correlated methods. Four clusters consisting mostly of hydrophobic residues were detected by nuclear Overhauser spectroscopy, two of which involved the tryptophan side chains. Extensive similarities to nuclear Overhauser spectroscopy data collected on the carbonmonoxy form of holomyoglobin suggested tentative assignments for several residues. It appeared that distinct cores of side chains on the distal side of the binding pocket and between the A, B, G, and H helices maintain the same packing as they do in holomyoglobin and apomyoglobin reconstituted with protoporphyrin IX.
Cocco
M J
MJ
Department of Chemistry, Pennsylvania State University, University Park 16802.
Lecomte
J T
JT
D000595:Amino Acid Sequence; D000818:Animals; D001059:Apoproteins / Q000737:chemistry*; D003903:Deuterium; D017666:Deuterium Oxide; D006736:Horses; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D008969:Molecular Sequence Data; D009211:Myoglobin / Q000737:chemistry*; D011485:Protein Binding; D011487:Protein Conformation; D011522:Protons; D014867:Water
D001059:Apoproteins; D009211:Myoglobin; D011522:Protons; C010857:apomyoglobin; D014867:Water; D003903:Deuterium; D017666:Deuterium Oxide