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. 2021 Aug 18;4:980. doi: 10.1038/s42003-021-02490-7

Table 1.

Thermodynamic data for purified variants of CI2 identified with the folding sensor.

Variant Tm (K) ΔHm (kJ mol−1) ΔCp (kJ mol−1 K−1) m (kJ mol−1  M−1) ΔGf (kJ mol−1) [D]50% (M) ΔΔGf (kJ mol−1)
aI30K, I57A 327.4 ± 3.1 −99 ± 11 −0.4 ± 0.8 8.8 ± 1.8 −8.2 ± 0.6 0.9 ± 0.2
A16D, P33Q, G35E, V38M, Q59K 333.3 ± 1.9 −134 ± 9 −2.6 ± 0.3 5.4 ± 0.5 −9.1 ± 0.6 1.7 ± 0.2
K18E, P33Q, V47D 336.0 ± 1.7 −147 ± 10 −2.9 ± 0.1 4.3 ± 0.2 −10.1 ± 1.0 2.3 ± 0.2
aI44N, I57A 339.0 ± 2.4 −163 ± 28 −2.6 ± 0.4 7.4 ± 1.5 −13.0 ± 2.8 1.8 ± 0.5
A27V, D52G 341.7 ± 1.0 −211 ± 19 −3.6 ± 0.3 6.0 ± 0.8 −16.4 ± 1.5 2.7 ± 0.4
aE41G, F50L, I57A 331.6 ± 0.5 −191 ± 3 −1.5 ± 0.1 11.5 ± 0.2 −16.6 ± 0.4 1.4 ± 0.0
A16T, N56I 339.4 ± 0.6 −227 ± 19 −4.1 ± 0.3 7.0 ± 0.4 −17.0 ± 1.5 2.4 ± 0.2
aV31D, I57A 344.7 ± 0.5 −222 ± 0 −3.7 ± 0.0 7.0 ± 0.0 −17.7 ± 0.1 2.5 ± 0.0
aI57A 333.1 ± 0.5 −269 ± 14 −5.4 ± 0.5 11.6 ± 0.6 −17.9 ± 0.6 1.5 ± 0.1
G10E, T39S 339.7 ± 0.7 −238 ± 16 −4.0 ± 0.7 8.5 ± 0.5 −18.4 ± 0.4 2.2 ± 0.1
aM40T, R48S, I57V 344.3 ± 0.3 −235 ± 9 −3.8 ± 0.2 7.1 ± 0.1 −19.1 ± 0.4 2.7 ± 0.1
G35W, A58V 336.8 ± 0.1 −281 ± 19 −5.7 ± 0.5 6.9 ± 0.2 −19.1 ± 0.9 2.8 ± 0.1
E4G 341.5 ± 0.1 −259 ± 7 −4.0 ± 0.2 7.3 ± 0.1 −21.4 ± 0.3 2.9 ± 0.1
L32Q, I57S 348.1 ± 0.6 −275 ± 5 −4.4 ± 0.0 6.1 ± 0.2 −22.9 ± 0.7 3.8 ± 0.2
V13E 343.1 ± 0.2 −280 ± 23 −4.1 ± 0.5 9.6 ± 0.6 −24.0 ± 1.6 2.5 ± 0.2
aE15G, M40T, R48C, I57V 347.6 ± 0.1 −281 ± 8 −4.1 ± 0.1 8.3 ± 0.2 −24.9 ± 0.7 3.0 ± 0.1
aV38E, I57V 348.8 ± 0.3 −295 ± 16 −4.4 ± 0.3 8.9 ± 0.5 −25.8 ± 1.2 2.9 ± 0.2
T39A, I57N 343.5 ± 0.2 −312 ± 0 −4.7 ± 0.0 10.6 ± 0.1 −26.4 ± 0.1 2.5 ± 0.0
L49I 350.3 ± 0.2 −322 ± 8 −4.6 ± 0.1 8.7 ± 0.2 −28.9 ± 0.8 3.3 ± 0.1 3.4 ± 0.1
V34E, D45Y 344.3 ± 0.0 −363 ± 7 −6.0 ± 0.2 8.4 ± 0.2 −29.2 ± 0.5 3.5 ± 0.1
wild-type 352.3 ± 0.2 −322 ± 11 −4.3 ± 0.2 8.2 ± 0.1 −30.5 ± 0.8 3.7 ± 0.1 0
P33L 354.1 ± 0.5 −330 ± 43 −4.2 ± 0.7 8.3 ± 0.8 −32.5 ± 3.5 3.9 ± 0.6
aL49I, I57V 356.2 ± 0.3 −332 ± 13 −4.2 ± 0.2 7.9 ± 0.4 −32.9 ± 1.3 4.2 ± 0.3 −3.8 ± 0.1
aI57V 354.5 ± 0.2 −349 ± 12 −4.7 ± 0.2 8.3 ± 0.2 −33.3 ± 0.9 4.0 ± 0.1 −2.2 ± 0.1
aD55G, I57V 361.6 ± 0.3 −364 ± 13 −4.3 ± 0.2 8.5 ± 0.2 −38.1 ± 0.8 4.5 ± 0.1 −6.5 ± 0.2
D55G 361.1 ± 0.1 −378 ± 10 −4.7 ± 0.1 8.5 ± 0.2 −38.4 ± 1.0 4.5 ± 0.2 −6.9 ± 0.3

aVariant selected from the I57A library.

Tm, is the melting temperature in the absence of denaturant. ΔHm is the enthalpy change for folding at Tm. ΔCp is the change in heat capacity for folding. m is the m-value for GuHCl unfolding. ΔGf is the free energy for folding at 298 K. [D]50% is the midpoint for the GuHCl unfolding at 298 K and ΔΔGf is the change in stability at 298 K relative to wild-type from a fit of six variants with a common m-value of 8.4 ± 0.3 kJ mol−1 M−1. The errors are the propagated standard errors from the global fits of the data.