title: [Nitrotyrosyl]cytochrome c. Studies of the effect of iron binding, protein denaturants and oxidation-reduction potentials.
abstract: Static measurements of the reaction of ligand binding were done by conventional spectrophotometry. The ligand-binding reactions with nitrated cytochrome c were performed with imidazole, iminazole, CO and NO. The stoicheiometry was found to be 1:1, and the stability constants for the complexes formed between the nitrated cytochrome c and the ligands are: 2.58 X 10(4) M-1 (imidazole); 1.01 X 10(2) M-1 (iminazole); 3.6 X 10(4) M-1 (CO); 2.74 X 10(4) M-1 (NO). It was found that the electrometric potentials at pH 7.0 and 25degreesC of [aminotyrosyl]cytochrome c are E'o form II = 0.115 V and E'o form I = 0.260 V, where forms I and II are two species of protein co-existing in the protein solution. The isoelectric point for the oxidized form of [nitrotyrosyl]cytochrome c was 10.05, at 4degreesC.
mesh_terms: D002248:Carbon Monoxide / Q000494:pharmacology; D003574:Cytochrome c Group / Q000031:analogs & derivatives*; D006146:Guanidines / Q000494:pharmacology; D007093:Imidazoles / Q000494:pharmacology; D007501:Iron; D007526:Isoelectric Point; D009569:Nitric Oxide; D010084:Oxidation-Reduction; D011485:Protein Binding; D011489:Protein Denaturation; D013053:Spectrophotometry; D013696:Temperature; D014443:Tyrosine / Q000031:analogs & derivatives
chemical_list: D003574:Cytochrome c Group; D006146:Guanidines; D007093:Imidazoles; D009569:Nitric Oxide; D014443:Tyrosine; D002248:Carbon Monoxide; D007501:Iron