TABLE 1.
Chemical shift fingerprint of the nature of the sixth heme iron ligand in HasAWT and its mutants
Diagnostic values are associated with the average heme-methyl 1H chemical shift, chemical shift of HNδ1 of His32, and 13C average chemical shift for the hyperfine shifted resonances of His32.
| Protein | HasAWT(10) | H83A (13) | Y75A (A form) (Ref. 10 and this work) | |||
|---|---|---|---|---|---|---|
| Axial ligation | His32-Fe-Tyr75 | His32-Fe | His32-Fe-H2Oδ− | His32-Fe-OH− | His32-Fe-H2Oδ− | |
| 1H CH3 | 40.0 | 71.3 | 54.0 | 35.2 | 51.2a | 45.9b |
| His32 HNδ1 | 66.3 | 103 | NDc | ND | 73.6 | 61 |
| 13C H32 | 439.1 | 530.4 | ND | ND | 475.1 | ND |
a Data were at pH 5.6.
b Data were at pH 9.5.
c ND means not determined.