Table 2.
Core mutants: thermodynamic and kinetic parameters and calculation of Φ-values
| Domain identifier | Protein identifier | Ka (104 M−1) | ΔΔGD–N (kcal mol−1) | k− (10−4 M−1 s−1) | Φa | ||
|---|---|---|---|---|---|---|---|
| Wild type | 207 (±8) | — | 4.7 (±0.3) | — | |||
| β16β17 | |||||||
| Helix A | |||||||
| F11A | F2014A | 0.6 (±0.6) | 3.5 (±0.6) | 2500 (±170) | −0.08 (±0.17) | ||
| F11L | F2014L | 1.6 (±0.2) | 2.93 (±0.09) | 680 (±40) | −0.02 (±0.04) | ||
| A15G | A2018G | 0.6 (±0.1) | 3.51 (±0.11) | 740 (±50) | 0.14 (±0.03) | ||
| A18G | A2021G | 13 (±3) | 1.67 (±0.13) | 35 (±3) | 0.28 (±0.07) | ||
| E19A | E2022A | 9.3 (±5) | 1.9 (±0.3) | 48 (±3) | 0.25 (±0.13) | ||
| L22A | L2025A | 0.6 (±0.1) | 3.50 (±0.13) | 470 (±30) | 0.21 (±0.03) | ||
| Q25A | Q2028A | 12 (±3) | 1.80 (±0.14) | 27 (±1) | 0.39 (±0.06) | ||
| Y28A | Y2031A | 18 (±2) | 1.47 (±0.08) | 41 (±3) | 0.12 (±0.06) | ||
| Y28L | Y2031L | 17 (±5) | 1.50 (±0.19) | 40 (±3) | 0.15 (±0.11) | ||
| L29A | L2032A | 29 (±2) | 1.18 (±0.05) | 19 (±2) | 0.29 (±0.07) | ||
| Helix B | |||||||
| V41A | V2044A | 42 (±4) | 0.96 (±0.06) | 8.3 (±0.5) | 0.65 (±0.07) | ||
| H48Ab | H2051A | — | — | — | — | ||
| F51Ab | F2054A | — | — | — | — | ||
| F51L | F2054G | 18 (±3) | 1.47 (±0.11) | 6.2 (±0.4) | 0.89 (±0.04) | ||
| T55Ab | T2057A | — | — | — | — | ||
| F62A | F2065A | 1.3 (±0.9) | 3.0 (±0.4) | 640 (±40) | 0.3 (±0.14) | ||
| F62L | F2065L | 10 (±2) | 1.46 (±0.04) | 48 (±3) | 0.05 (±0.06) | ||
| L65Ab | L2068A | — | — | — | — | ||
| α0α1 | |||||||
| Helix C | |||||||
| Q88Ac | Q29A | 100 (±20) | 0.42 (±0.1) | 5.3 (±0.4) | — | ||
| L91Ac,d | L32A | 130 (±30) | 0.27 (±0.14) | — | — | ||
| Y94Ac | Y35A | 67 (±2) | 0.68 (±0.03) | 148 (±10) | — | ||
| Y94Lc,d | Y35L | 440 (±50) | −0.45 (±0.07) | 50 (±4) | |||
| F97A | F38A | 5.8 (±0.7) | 2.14 (±0.07) | 420 (±3) | −0.27 (±0.05) | ||
| F97Le | F38L | — | — | — | — | ||
| V101A | V42A | 10 (±2) | 1.80 (±0.13) | 18 (±12) | 0.6 (±0.2) | ||
| R104A | R45A | 670 (±190) | −0.70 (±0.17) | 3 (±3) | 0.7 (±0.8) | ||
| L108Ab | L49A | — | — | — | — | ||
a
Φ calculated using 〈mk−〉 = 1.2 M−1.
b
Mutation abolished formation of the tetramer domain, as judged by ITC.
c
ΔΔGD–N < 0.7 kcal mol−1; Φ not calculated.
d
Slope of unfolding limb ≠ 1.2 M−1.
e
Protein insoluble.