Table 2.
Spin-Hamiltonian parameters used to model the EPR spectra shown in Fig. 2C
| Samples | EPR active signal | Species | % | g1 | g2 | g3 | gave |
|---|---|---|---|---|---|---|---|
| As-isolated CntA | 2.0105 | 1.9157 | 1.7574 | 1.8945 | |||
| As-isolated CntB | No EPR active signal detected | ||||||
| CntB+NADH | [2Fe-2S]+1 | specA (reduced ferredoxin domain) | 93 | 2.0314 | 1.9372 | 1.8988 | 1.9558 |
| Flavin radical | specB (Flavin radical) | 7 | 2.0015 | 2.0015 | 2.0015 | 2.0015 | |
| CntA+CntB+NADH | [2Fe-2S]+1 in CntB | specA (reduced ferredoxin domain) | 61 | 2.0313 | 1.9376 | 1.8979 | 1.9556 |
| Flavin radical | specB | 2 | 2.0010 | 2.0034 | 2.0039 | 2.0028 | |
| [2Fe-2S]+1 in CntA | specC (reduced Rieske center) | 37 | 2.0079 | 1.9153 | 1.7542 | 1.8924 | |
| CntA+CntB+NADH+Carnitine | an organic radical | specB | 34 | 2.0000 | 2.0035 | 2.0037 | 2.0024 |
| [2Fe-2S]+1 in CntAa | specC | 66 | 2.0071 | 1.9077 | 1.7986 | 1.9045 | |
| E205A+CntB+NADH+Carnitine | [2Fe-2S]+1 in CntB | specA1 | 40 | 2.0338 | 1.9397 | 1.8868 | 1.9534 |
| [2Fe-2S]+1 in CntB | specA2 | 20 | 2.0449 | 1.9493 | 1.9037 | 1.9660 | |
| Flavin radicalb | specB | 8 | 2.0012 | 2.0040 | 2.0040 | 2.0031 | |
| [2Fe-2S]+1 in CntAa | specC | 32 | 2.0070 | 1.9077 | 1.7896 | 1.9014 | |
a
This EPR active signal may also contain overlapping EPR signals derived from the catalytic mononuclear iron center; plausible EPR active intermediates are ferric-(hydro)peroxy or a high-valent iron(V)-oxo species.
b
This may represent an overlay of both a flavin and an unidentified organic radical.