Morishima, Isao published the artcileProton NMR study of hemoproteins. Ionization and orientation of iron-bound imidazole in methemoglobin and metmyoglobin, Application of 5-Fluoro-1H-imidazole, the main research area is methemoprotein imidazolyl ionization orientation; imidazolylmethemoprotein ligand ionization orientation; imidazolylmetHb ionization heme orientation; imidazolylmetmyoglobin ionization heme orientation; heme orientation imidazolylmethemoprotein ligand.
Characteristics of imidazole derivatives bound to metHb and metmyoglobin (MetMb) were investigated by H NMR spectroscopy with special regard to the ionization of the imino proton and orientation of the imidazole ring in the heme crevice. The hyperfine-shifted heme Me resonances of MetMb complexes with imidazole, 4-methylimidazole, and triazole were pH dependent, whereas those of the N-methylimidazole complex were pH independent. The pH-dependent shifts in the former complexes were attributed to the deprotonation of the imino proton of imidazole derivatives bound to the heme Fe. In contrast, MetMb complexes with 4-nitroimidazole and 4-fluoroimidazole, both of which have the ionizable NH proton, did not exhibit such pH-dependent shifts, indicating restricted orientation of the Fe-bound 4-nitroimidazole and 4-fluoroimidazole in the heme crevice, where the imino proton is not exposed to the solvent sphere. In the MetMb-imidazole complex, however, pH dependence of the hyperfine shifts was observed, in contrast to the case of imidazole-MetMb. This was also interpreted as arising from the specific orientation of the Fe-bound exogenous imidazole in the MetMb heme pocket. Two sets of heme Me proton resonances were detected for the 4-fluoroimidazole-MetMb complex and these were attributed to the 2 tautomeric forms of the Fe-bound 4-fluoroimidazole. The relative proportion of the 2 tautomers was dependent on both pH and temperature The temperature dependence of the hyperfine shifts of the 2 species indicated that they are in a single spin state.
Biochimica et Biophysica Acta, Protein Structure published new progress about Ionization. 30086-17-0 belongs to class imidazoles-derivatives, name is 5-Fluoro-1H-imidazole, and the molecular formula is C3H3FN2, Application of 5-Fluoro-1H-imidazole.
Referemce:
Imidazole – Wikipedia,
Imidazole | C3H4N2 – PubChem