title: N.m.r. and e.p.r. characterization of [4-carboxy-2,6-dinitrophenyl-lysine]cytochromes c.
abstract: Monosubstituted [4-carboxy-2,6-dinitrophenyl-lysine]cytochromes c were investigated by n.m.r. and e.p.r. Modification of Lys-13 or Lys-72 in ferricytochrome c by 4-chloro-3,5-dinitrobenzoate yields either of two different conformers that are rapidly exchanging in the native form. The equilibrium involves small local changes in the conformation of Met-80 (the sixth ligand) and Phe-82, as a result of whether Lys-13 is the 'on' or 'off' position in the Lys-13--Glu-90 salt bridge.
mesh_terms: D003574:Cytochrome c Group / Q000031:analogs & derivatives*; D004578:Electron Spin Resonance Spectroscopy; D006863:Hydrogen-Ion Concentration; D009682:Magnetic Resonance Spectroscopy
chemical_list: D003574:Cytochrome c Group