TABLE 1.
1H NMR chemical shifts for the ligating cysteine Hβ protons from the Ni(II) and Fe(II) forms of Dv and Cp rubredoxin respectively and published chemical shifts for a number of Ni(II) containing azurin-like proteins. Dihedral angles for the Cα carbon of the cysteines ligating the metal atom in DvRd(Fe), CpRd(Ni) and CpRd(Fe) are taken from the x-ray structures 8RXN, 1R0J and 5RXN respectively. The average NMR chemical shifts for the cysteine Hβ protons in DvRd(Ni) and CpRd(Fe) are included along with the number of HN-S hydrogen bonds each cysteinyl sulfur is involved in. The structural data for the azurin-like proteins are for the native Cu forms and the NMR data for the Ni(II) derivatives.
| Hβ | δobs | δ1/2 | M-Sγ-Cβ-Cα | HN-S H-bondsg |
||
|---|---|---|---|---|---|---|
| DvRd(Ni) | C9/C42 | a(c) | 362 (279) | 321/320 | −94.35/−89.658RXN | 1 |
| C42/C9 | b(d) | 360 (269) | 321/320 | −89.65/−94.35 | 1 | |
| C6 proR | e(h) | 198 (161) | 183 | −172.69 | 2 | |
| C39 proR | f(g) | 188 (167) | 178 | −175.33 | 2 | |
| CpRd(Fe) | C42 proS | a(c) | 251 (233) | 242a | −83.85RXN | 1 |
| C9 proS | b(d) | 244 (233) | 239a | −90.5 | 1 | |
| C6 proR | e(h) | 196 (157) | 178a | −177.7 | 2 | |
| C39 proR | f(g) | 193 (159) | 176a | −178.2 | 2 | |
| CpRd(Ni) | C42 | −84.71R0J | 1h | |||
| C9 | −95.2 | 1 | ||||
| C6 | −167.7 | 2 | ||||
| C39 | −178.8 | 2 | ||||
| UMC | C85 proS | 224(167) | 196b | −169.61X9U | 2 | |
| AZ | C112 proS | 238 (197) | 218c | −161.42AZA | 2 | |
| AZ | C112 proS | 233 (187) | 210d | −171.04AZU | 2 | |
| AZM121Q | C112 proS | 237(178) | 208c | 169.11URI | 2 | |
| AZ | C112 proS | 238(194) | 216j | −172.72CCW | 2 | |
| STC | C87 proS | 197(177) | 187e | −176.21JER - CsSTC | 2 | |
| PA | C78 proS | 297 (274) | 285f | −169.21BQK | 1 | |
| AMI | C93 proS | 254 (296) | 275i | −171.61ID2 | 1 |