Table 1

Spectroscopic, stability, and kinetic properties of mutants

MutantsEllipticity 222 nm, mdegFluorescence center of mass, nmTm, °C ΔGu, kcal/mol Reduction in unfolding rate2Increase in refolding rate3
ObservedPredicted1ObservedPredicted1
3A−73.1336.557.7 ± 0.6 56.6 ± 1.1 10.9 ± 0.9 0.92
7A−69.4339.559.8 ± 0.6 54.9 ± 1.6 12.1 ± 1.3 2.9
11A−70.5338.269.2 ± 0.6 54.7 ± 2.0 7.3 ± 1.715.4
12A−70.5339.971.1 ± 0.6 59.8 ± 2.1 16.0 ± 0.5 7.3 ± 1.731.034.2
15A−70.8340.172.3 ± 0.6 59.1 ± 2.3 15.2 ± 0.5 7.2 ± 1.953.526.6
Arc-native−69.4336.757.9 ± 0.6 57.9 ± 0.6 11.0 ± 0.5 11.0 ± 0.5 1.01.0
Arc-denatured4351.4
  • 1 Calculated based on sum of ΔTms and ΔΔGus for the single mutants (23). 

  • 2 Relative to wild-type Arc-st11 values in 4.6 M urea for 3A and 7A and in 4.5 M GuHCl for 11A, 12A, and 15A. 

  • 3 Relative to wild-type Arc-st11 value of 1.05⋅107 M−1⋅s−1 (27). 

  • 4 Denatured in 6 M GuHCl.