TABLE 1.
Best-fit values and estimates of the c(s,f/f0) analyses of NEU1, PPCA, and the PPCA-NEU1 heterodimeric complex
| Sample (mg/ml) | pH | s4a (Svedberg) | s20,w0b (Svedberg) | f/f0c (s20,w0) | Mrd | Protein complex |
|---|---|---|---|---|---|---|
| kDa | ||||||
| NEU1 (0.25) | 5 | 3.20 (0.11) | 5.15 | 1.43 (1.43) | 93 (95) | Dimer |
| 4.40 (0.08) | 7.08 | 1.65 (1.65) | 185 (190) | Tetramer | ||
| PPCA (0.22) | 5 | 3.77 (0.16) | 6.07 | 1.34 (1.30) | 110 (111) | Dimer |
| PPCA-NEU1 (0.25) | 5 | 3.77 (0.147) | 6.07 | 1.24 (1.28) | 100 (103) | Heterodimer |
| NEU1 (0.45) | 7 | 3.05 (0.10) | 4.94 | 1.46 (1.49) | 94 (95) | Dimer |
| 3.65 (0.07) | 5.91 | 1.25 (1.25) | 96 (95) | Dimer | ||
| 4.72 (0.07) | 7.77 | 1.90 (2.00) | 270 (285) | Hexamer |
a Sedimentation coefficient at 4 °C (s4) taken from the ordinate maximum of each peak in the best-fit c(s,f/f0) distribution. The relative amount of each species is given in parenthesis.
b Converted s values of the best-fit c(s,f/f0) distribution data to s20,w0 values. Standard conditions: 20 °C, water as the solvent, and zero protein concentration were used.
c Frictional ratio (f/f0) obtained from the calculated c(s,f/f0) distribution, and the ratio was calculated with SENTERP.
d Molar mass values were obtained from the calculated c(s,f/f0) distribution and transformed to the c(s,Mr) distribution (41).