Table 1. Hydrodynamic analysis of SSB variants at 25°C in buffer T.
Protein | 300 mM NaCl | 2 mM NaCl | ||
---|---|---|---|---|
s20,w | f/f0 | s20,w | f/f0 | |
SSB | 4.23 | 1.51 | 4.51 | 1.49 |
SSB LD | 4.13 | 1.43 | 4.31 | 1.42 |
SSB LD (αΔW) | 4.02 | 1.43 | 4.25 | 1.42 |
SSB LD (αΔW F) | 3.81 | 1.61 | 4.15 | 1.39 |
βΔW | 4.00 | 1.43 | 4.24 | 1.45 |
Analysis was performed via analytical ultracentrifugation sedimentation velocity at [4-OB] = 750 nM. Each variant predominately formed the 4-OB fold species yielding molecular weights within 10% of their expected values in moderate salt and in low salt. Most experiments performed on variants of SSB LD had some amount of a high molecular weight species present that corresponded to the MW of a dimer of the 4-OB fold species. This high molecular weight species never accounted for more than 4% of the total signal in the experiment.