Table 2. Predictedaand Experimentalb,cRh Values (nanometers) and Compaction Factorsd (Cf) for αS, βS, and βSHC in Various States.
U | F | NaClb | NaCl and SDSc | ||
---|---|---|---|---|---|
αS | Rh | 3.70 | 1.99 | 3.19 | 2.46 |
Cf | 0.61 | 0.30 | 0.725 | ||
βS | Rh | 3.60 | 1.97 | 3.24 | 3.22 |
Cf | – | 0.22 | 0.23 | ||
βSHC | Rh | 3.77 | 2.01 | – | 2.97 |
Cf | – | – | 0.46 |
U and F refer to the Rh values predicted according to eq 7(27) for a fully unfolded and a compact folded polypeptide, respectively.
Measured by PFG-NMR on 200 μM protein in D2O and 20 mM phosphate buffer (pH 6.5) with 100 mM NaCl at 288 K.13 Note that the Rh measured by PFG-NMR for 100 μM αS in unbuffered D2O at 288 K is almost identical (3.20 nm).126
Measured by PFG-NMR on 70 μM protein in 10 mM phosphate buffer (pH 7.7) with 100 mM NaCl and 0.5 mM SDS at 298 K.129