Effect of EPP mutations on homodimeric and heterodimeric human ferrochelatases kinetic parameters
. | Homodimers . | . | . | Heterodimers . | . | . | ||||
|---|---|---|---|---|---|---|---|---|---|---|
| Mutant . | KmFe, μM . | KmMeso, μM . | kcat, min-1 . | KmFe, μM . | KmMeso, μM . | kcat, min-1 . | ||||
| WT | 11.9 ± 2.3 | 12.1 ± 2.0 | 3.4 ± 0.2 | 11.4 ± 1.6 | 9.4 ± 1.3 | 2.6 ± 0.1 | ||||
| Q139L | 26.2 ± 4.1 | 26.7 ± 4.3 | 0.6 ± 0.1 | 21.9 ± 3.8 | 9.2 ± 1.4 | 1.6 ± 0.1 | ||||
| Y191H | 25.1 ± 4.7 | 12.9 ± 2.5 | 2.6 ± 0.6 | 38.0 ± 8.7 | 17.2 ± 1.9 | 1.8 ± 0.2 | ||||
| C236Y | 14.1 ± 2.6 | 30.2 ± 6.9 | 0.9 ± 0.1 | 17.9 ± 3.9 | 12.9 ± 1.3 | 0.7 ± 0.1 | ||||
| F260L | 76.3 ± 14.7 | 14.6 ± 2.1 | 1.8 ± 0.1 | 44.1 ± 9.0 | 9.7 ± 1.5 | 0.9 ± 0.1 | ||||
| S264L | ND | ND | 0 | 23.5 ± 4.3 | 13.8 ± 2.8 | 1.7 ± 0.1 | ||||
| M267I | 11.7 ± 1.2 | 12.3 ± 2.0 | 3.2 ± 0.1 | 8.3 ± 1.3 | 6.1 ± 1.1 | 2.5 ± 0.1 | ||||
| P334L | 48.8 ± 14.0 | 18.2 ± 3.3 | 0.6 ± 0.1 | ND | ND | 0 | ||||
| K379N | 110.1 ± 26.1 | 22.4 ± 3.4 | 2.0 ± 0.1 | 23.2 ± 4.3 | 25.3 ± 3.4 | 1.6 ± 0.1 | ||||
. | Homodimers . | . | . | Heterodimers . | . | . | ||||
|---|---|---|---|---|---|---|---|---|---|---|
| Mutant . | KmFe, μM . | KmMeso, μM . | kcat, min-1 . | KmFe, μM . | KmMeso, μM . | kcat, min-1 . | ||||
| WT | 11.9 ± 2.3 | 12.1 ± 2.0 | 3.4 ± 0.2 | 11.4 ± 1.6 | 9.4 ± 1.3 | 2.6 ± 0.1 | ||||
| Q139L | 26.2 ± 4.1 | 26.7 ± 4.3 | 0.6 ± 0.1 | 21.9 ± 3.8 | 9.2 ± 1.4 | 1.6 ± 0.1 | ||||
| Y191H | 25.1 ± 4.7 | 12.9 ± 2.5 | 2.6 ± 0.6 | 38.0 ± 8.7 | 17.2 ± 1.9 | 1.8 ± 0.2 | ||||
| C236Y | 14.1 ± 2.6 | 30.2 ± 6.9 | 0.9 ± 0.1 | 17.9 ± 3.9 | 12.9 ± 1.3 | 0.7 ± 0.1 | ||||
| F260L | 76.3 ± 14.7 | 14.6 ± 2.1 | 1.8 ± 0.1 | 44.1 ± 9.0 | 9.7 ± 1.5 | 0.9 ± 0.1 | ||||
| S264L | ND | ND | 0 | 23.5 ± 4.3 | 13.8 ± 2.8 | 1.7 ± 0.1 | ||||
| M267I | 11.7 ± 1.2 | 12.3 ± 2.0 | 3.2 ± 0.1 | 8.3 ± 1.3 | 6.1 ± 1.1 | 2.5 ± 0.1 | ||||
| P334L | 48.8 ± 14.0 | 18.2 ± 3.3 | 0.6 ± 0.1 | ND | ND | 0 | ||||
| K379N | 110.1 ± 26.1 | 22.4 ± 3.4 | 2.0 ± 0.1 | 23.2 ± 4.3 | 25.3 ± 3.4 | 1.6 ± 0.1 | ||||
Data for each parameter are from 10 assays, and reported values represent the average of 3 replications of each assay.
WT indicates wild type; ND, not done.