TABLE 1.
SEC-MALS and SV analyses of SMN·Gemin2 complexes
Plasmid numbers refer to internal laboratory database entries for the plasmids used for expression or co-expression. Calculated complex molecular masses are for a 1:1 stoichiometry. SEC-MALS concentration is at the UV absorbance peak, as determined by refractive index. MA, apparent molecular mass based on calibration of the SEC column with globular standards; M̄w, weight-average molecular mass from MALS; ND, not determined.
| Complex | Plasmid | Mcalc | SEC-MALS (20 °C) |
SV (20 °C) |
SV (4 °C) |
||||
|---|---|---|---|---|---|---|---|---|---|
| Concentration | MA | M̄w | Concentration | s20,w | Concentration | s20,w | |||
| kDa | μm | kDa | kDa | μm | μm | ||||
| hGemin2 | 371 | 30.8 | 2.3 | 56.3 | 27.7 ± 0.1 | ND | ND | ||
| hSMN(26–51)·Gemin2 | 1449/371 | 33.7 | 1.9 | 54.4 | 31.7 ± 0.3 | ND | ND | ||
| hSMN(14–156)·Gemin2 | 384 | 46.6 | 4.7 | 74.6 | 44.4 ± 0.2 | ND | 21 | 1.9 | |
| hSMN(14–209)·Gemin2 | 2150/371 | 52.3 | 2.8 | 86.8 | 62.1 ± 2.4 | 32 | 3.1 | ND | |
| hSMN·Gemin2 | 400 | 62.3 | 0.14 | > 670 | 200–600 | 4 | 11–12a | 4 | 5–6 |
| SMNΔ5·Gemin2 | 408 | 58.4 | 0.7 | > 670 | 200–454 | 4 | 11–12a | 4 | 5–6 |
| 0.5 | > 670 | 236–368 | ND | ND | |||||
| 0.4 | > 670 | 175–280 | ND | ND | |||||
| SMNΔ7·Gemin2 | 401 | 61.1 | 0.2 | 100 | 66.0 ± 7.9 | ND | ND | ||
| ySMN·Gemin2 | 1173/414 | 44.7 | 1.3 | 305 | 110–180 | 10.3 | 5–8 | 24 | 4–5 |
| 0.4 | 256 | 51–160 | ND | ND | |||||
| 0.13 | 164 | 54–95 | ND | ND | |||||
| MBP-hSMN(229–294) | 1736 | 48.3 | 0.9 | 128 | 200–410 | 10.2 | 10–11 | 10.2 | 7–8 |
| MBP-ySMN(39–152) | 1774 | 53.7 | 0.5 | 337 | 189.1 ± 13.6 | ND | ND | ||
a Measurements performed at 25 °C.