title: H NMR probes for inter-segmental hydrogen bonds in myoglobins.
abstract: NMR signals arising from the HisB5 N delta H and HisEF5 N epsilon H protons in sperm whale skeletal and horse heart myoglobins have been located for the first time in the downfield shifted portion of the spectra. The shifts and hydrogen exchange rates indicate that these His imidazole ring NH protons are involved in the inter-segmental hydrogen bonds of the protein in solution, as demonstrated by a crystallographic study [Takano, T. (1977) J. Mol. Biol. 220, 381-399]. The assigned His imidazole ring NH proton resonances can serve as new sensitive structural probes in the study of the local conformation of myoglobin. The applicability of the NMR spectral parameters in the study of the tertiary structure of apomyoglobin, the denaturation of the protein, and the protein stability of sperm whale and horse myoglobins is presented in some detail.
authors.affiliation: Department of Chemistry, University of Tsukuba, Ibaraki.
authors.forename: Y
authors.initials: Y
authors.lastname: Yamamoto
mesh_terms: D000818:Animals; D001059:Apoproteins / Q000737:chemistry*; D006639:Histidine / Q000737:chemistry; D006736:Horses; D006860:Hydrogen Bonding; D006863:Hydrogen-Ion Concentration; D009682:Magnetic Resonance Spectroscopy; D009211:Myoglobin / Q000737:chemistry*; D011489:Protein Denaturation; D017434:Protein Structure, Tertiary; D014907:Whales
chemical_list: D001059:Apoproteins; D009211:Myoglobin; C010857:apomyoglobin; C018013:carboxymyoglobin; D006639:Histidine