Table 1.
Summary of sedimentation equilibrium resultsa,b
| Construct | Sequence MMc (kDa)c | Speed (krpm)c | Measured MM at 60 μM (kDa) | Measured MM at 160 μM (kDa) | Predominant Oligomeric State |
|---|---|---|---|---|---|
| NarLC (147–216) | 9.6 | 15 | 9.7 | 12.3 | Monomer |
| 22 | 9.6 | 11.4 | |||
| NarLC (126–216) | 11.8 | 15 | 14.1 | 13.6 | Monomer |
| 22 | 12.7 | 12.4 | |||
| NarL | 23.9 | 11 | 24.0 | 23.9 | Monomer |
| 15 | 22.6 | 23.0 | |||
| NarLN | 16.5 | 15 | 26.1 | 25.9 | Monomer/Dimer |
| 22 | 23.4 | 23.0 | |||
| NarLN-P | 16.6 | 15 | 30.8 | 30.4 | Dimer |
| 22 | 29.0 | 27.4 |
aCertain constructs had additional data collected at other speeds that are not shown in the table but were included in determining the best oligomeric fit (discussed in text)
bAll runs shown were carried out in a buffer solution containing 25 mM Tris, pH 7.5-8.5 and 500 mM NaCl, except for two cases: NarLC (147–214) at 60 μM contained 500 mM (NH4)2SO4, and NarL at 60 μM contained 100 mM NaCl. These changes to salt did not significantly alter the measured molecular masses (see Materials and Methods)
cMM: molecular mass; kDa: kiloDalton; krpm: kilorevolutions per minute