Table 2.
Midpoint potentials of S. oneidensis ccNiR hemes (in volts vs. the standard hydrogen electrode) for wild type ccNiR (ccNiRwt) in the presence and absence of cyanide, and for the H268M mutant (ccNiRH268M). Colors and the labels H1 – H5 suggest possible assignments to the hemes in Fig. 1; see text for details.
| ccNiRwta | ccNiRwt + CN− | ccNiRH268M | |
|---|---|---|---|
| ɛ01 | −0.0440±002 (H1) | 0.027 (H1) | 0.060 (H5) |
| ɛ02 | −0.110±0.004 (H4) | −0.089 (H4) | −0.035 (H1) |
| ɛ03 | −0.21±0.02 (H2) | −0.185 (H2) | −0.116 (H4) |
| ɛ04 | −0.257±0.017 (H5) | −0.248 (H5) | −0.209 (H2) |
| ɛ05 | −0.382±0.004 (H3) | −0.388 (H3) | −0.338 (H3) |
a
Average of two experiments performed using the same apparatus, but different ccNiR batches. Experiments obtained using different spectroelectrochemical apparatus, or different techniques, exhibited greater variability in the midpoint potential values obtained (ref(10)).