Table 2.
Results of SEC, thermal unfolding properties by DSC, intrinsic tryptophan fluorescence and net surface charge (zeta potential) and diffusion interaction parameter (kD) of all test proteins.
| DSC |
SEC$–40C |
SEC$-5C | Trp FI | DLS |
|||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| CODE | ΔHapp (1st) Kcal/mol | ΔHapp (2nd) Kcal/mol | ΔHapp (total) Kcal/mol | Tonset (°C) | Tm1 (°C) | Tm2 (°C) | Δ %Monomer | Δ %LMW | Δ %HMW | Δ %Monomer | λmax (nm) | kD (L/g) | ZP (mV) |
| G4–1 | 246.7 | 797.6 | 1044.3 | 55.0 | 61.0 | 73.0 | 5.4 | 2.9 | 2.5 | 0.6 | 333 | 6.8 | 10.0 |
| G4–2 | 181.8 | 755.0 | 936.8 | 56.0 | 61.3 | 72.9 | 9.7 | 1.8 | 7.9 | 0.4 | 346 | 4.9 | 2.9 |
| G1–1 | 853.1 | 146.4 | 999.6 | 66.0 | 74.6 | 85.3 | 12.8 | 10.0 | 2.8 | 0.6 | 346 | 15.9 | 4.0 |
| G1–2 | 834.1 | 106.9 | 941.0 | 62.1 | 72.0 | 82.5 | 8.3 | 3.5 | 4.9 | 0.3 | 339 | −8.6 | 2.7 |
| G1–3 | 189.2 | 870.7 | 1059.8 | 62.0 | 71.1 | 83.6 | 7.1 | 6.3 | 0.9 | 0.1 | 335 | ND | 5.8 |
| G1–4 | 263.0 | 907.8 | 1170.7 | 60.3 | 69.6 | 83.0 | 6.7 | 4.5 | 2.2 | 0.1 | 336 | 17.2 | 7.8 |
| G1–5 | 271.9 | 1487.0 | 1758.9 | 60.2 | 67.6 | 80.9 | 15.8 | 13.7 | 2.0 | 0.2 | 335 | 24.0 | 6.1 |
| G1–6* | 611.3 | 347.6 | 1010.3 | 58.4 | 68.1 | 75.2 | 5.0 | 3.4 | 1.7 | 0.5 | 353 | ND | 2.0a |
| G1–7 | 1052.2 | 107.4 | 1159.6 | 58.4 | 71.6 | 81.5 | 13.6 | 8.3 | 4.3 | 1.1 | 340 | −3.9 | 3.3a |
ZP = Zeta Potential
*
third transition observed at 83.2°C with ΔHapp of 51.5 Kcal/mol
$
Δ=change in content between final and initial timepoints
a
diluted in 10 mM histidine buffer