Table 1.
Oligomeric state and conformational stability of the IgM Fc domains
| Domain | Mass, kDa | Kd, µM | ΔGunfolding, kJ⋅mol−1 | meq, kJ⋅mol−1⋅M−1 | Tmelt, °C |
| Cµ2 | 24.6 | — | 36.2 | 18.6 | 64.5 |
| Cµ2C337S | 23.6 | 2.1 ± 0.1 | 26.0 | 16.6 | 60.0 |
| Cµ3C414S | 11.3 | — | 15.8 | 10.2 | 57.9 |
| Cµ4 | 17.8* | 86 ± 3 | 15.8 | 14.4 | 58.9 |
| Cµ4tpC575S | 15.4* | 224 ± 7 | 21.1 | 17.5 | 60.9 |
Molar masses and Kd values for domain dimerization were calculated from SV and SE aUC runs, respectively.
*
For Cµ4 and Cµ4tpC575S, monomeric and dimeric species could not be separated due to fast exchange rates. ΔGunfolding and the cooperativity parameter (meq) originate from GdmCl denaturation experiments and melting temperature (Tmelt) from thermal denaturation experiments.