Assignment of fluorine nuclear magnetic resonance signals from rabbit cyanomethemoglobin.
A fluorine NMR study of cyanomethemoglobin prepared from hemoglobin isolated from rabbits maintained on a diet containing DL-p-fluorophenylalanine is described. The results indicate that substitution of fluorophenylalanine occurs essentially randomly at all phenylalanine positions of the alpha- and beta-globin chains; a set of hybrid hemoglobins in which only the alpha- or only the beta-chains contain the fluorinated amino acid was prepared and used to ascertain the fluorine NMR signals arising from each chain. The temperature and pH dependences of chemical shifts, spin-lattice relaxation times, 19F(1H) nuclear Overhauser effects, and the effect of chemical modification of the beta-93 sulfhydryl groups were examined. When considered in light of presently available X-ray structures of human and horse hemoglobins, the available data permit a tentative assignment of most signals to particular fluorophenylalanine/phenylalanine positions in the globin sequences.
D000596:Amino Acids / Q000032:analysis; D000818:Animals; D004578:Electron Spin Resonance Spectroscopy; D006454:Hemoglobins; D006863:Hydrogen-Ion Concentration; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D008433:Mathematics; D008706:Methemoglobin / Q000031:analogs & derivatives* / Q000032:analysis; D010446:Peptide Fragments / Q000032:analysis; D055503:Protein Multimerization; D011817:Rabbits; D014443:Tyrosine; D010135:p-Fluorophenylalanine / Q000378:metabolism
D000596:Amino Acids; D006454:Hemoglobins; D010446:Peptide Fragments; C007169:cyanomethemoglobin; D014443:Tyrosine; D010135:p-Fluorophenylalanine; D008706:Methemoglobin