Table 1. Calculated and observed molecular weight and scaffold stoichiometry of peptidiscs.
| Peptidisc | Molecular weight measured by ESI-MS (kDa) | Measured NSPr stoichiometry (NSPr/disc) | Measured lipid stoichiometry (Lipid/Disc) |
Calculated molecular weight* (kDa) |
|---|---|---|---|---|
| MalFGK2-NSPr | 247 ± 24 | 10 (±2): 1 | 41 (±10): 1 | 251 ± 12 |
| BRC-NSPr | 138 ± 18 | 9 (±1): 1 | 4 (±1): 1 | 138 ± 5 |
| FhuA-NSPr | 137 ± 18 | 10 (±2): 1 | 8 (±3): 1 | 131 ± 9 |
*The formula for the calculated molecular weight is as follows: MWpeptidisc = MW(protein)+n(MWNSPr)+m(MWLipid); where n is the measured NSPr stoichiometry, m is the measured lipid stoichiometry, MWLipid = 0.8 kDa, MWNSPr = 4.5 kDa, and MWprotein = 173 kDa, 80 kDa, and 94 kDa for MalFGK2, FhuA, and BRC, respectively. For NSPr and Lipid stoichiometry, the standard deviation is derived from three separate measurements.