Are the parameters of various stabilization factors estimated from mutant human lysozymes compatible with other proteins?

The various factors which contribute to protein stability havebeen extensively examined using mutant proteins, but the samekinds of substitutions have given different results dependingon the substitution sites. Recently, the contributions of somestabilization factors have been quantitatively derived as parametersby a unique equation, considering the conformational changesdue to the mutations using mutant human lysozymes Funahashiet al. (1999) Protein Eng. 12, 841–850]. To evaluate theseparameters estimated from the mutant human lysozymes, stability–structuredatasets for the mutant T4 lysozymes were selected. The stabilitiesfor the mutant T4 lysozymes could be roughly estimated usingthese parameters. Notable differences between the estimatedand experimental stabilities were caused by the uncertaintyin part of the structures due to some Arg and Lys residues fluctuatingon the surface of the T4 lysozyme. Excluding these atoms fromthe estimation gave a good correlation between the estimatedand experimental stabilities. These results suggest that theparameters of the various stabilization factors derived fromthe mutant human lysozymes are compatible with the mutant T4lysozymes, although they should be improved with respect tosome points using more information.