Table 2. PGRMC1 proteins exhibit haem-dependent dimerization in solution.
|
Apo form |
Haem-bound form |
|||
|---|---|---|---|---|
| Mass (Da) | Mass (Da) | |||
| a PGRMC1 wt (a.a.44–195) | ||||
| ESI-MS | — | 17,844.14 | — | 36,920.19 |
| Theoretical | 17,843.65 | 36,918.06 | ||
| Hydrodynamic radius 10−9 (m) | MW (kDa) | Hydrodynamic radius 10−9 (m) | MW (kDa) | |
| DOSY | 2.04–2.15 | 20 | 2.94–3.02 | 42 |
| S20,w (S) | MW (kDa) | S20,w (S) | MW (kDa) | |
| SV-AUC | 1.9 | 17.6 | 3.1 | 35.5 |
| b PGRMC1 C129S (a.a.44–195) | ||||
| ESI-MS | — | 17,827.91 | — | 36,887.07 |
| Theoretical | 17,827.59 | 36,885.6 | ||
| S20,w (S) | MW (kDa) | S20,w (S) | MW (kDa) | |
| SV-AUC | 2.0 | 18.1 | 3.1 | 35.8 |
Differences in molecular weights of the wild-type (wt; a) and the C129S mutant (b) PGRMC1 proteins in the absence (apo form) or the presence of haem (haem-bound form). The protein sizes of the wt and C129S PGRMC1 cytosolic domains (a.a.44–195) in the presence or absence of haem were estimated by ESI-MS, DOSY and SV-AUC.