Table 2.
EPR and UV-visible absorbance spectroscopic parameters of nitrosyl complexes formed in nonheme iron enzymes catalyzing thiol oxidatione
Protein | Protein ligand | Substrate coordination | Enzyme-nitrosyl complex | ES-nitrosyl complex |
---|---|---|---|---|
ADOa | 3-His | Monodentate, via thiol | {Fe(NO)}7, S = 3/2, g = 4.10, 3.95, 2.00; 340, 406 nm | {Fe(NO)2}9, S = 1/2, g = 2.04, 2.01; 390 or 397 nm |
CDOb | 3-His | Bidentate, via thiol and amine | {Fe(NO)}7, S = 3/2, g ∼ 4, 4, 2 | {Fe(NO)}7, S = 1/2, g = 2.07, 2.02, 1.98 |
3MDOc | 3-His | Unclear, thiol involved | Not applicable | {Fe(NO)}7, S = 3/2, g = 4.06, 3.96, 2.00 |
IPNSd | 2-His-2-carboxylate | Monodentate, via thiol | {Fe(NO)}7, S = 3/2, g = 4.09, 3.95, 2.00; 340, 430, 600 nm | {Fe(NO)}7, S = 3/2, g = 4.22, 3.81, 1.99; 508, 720 nm |