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

The various factors which contribute to protein stability have been extensi vely examined using mutant proteins, but the same kinds of substitutions ha ve given different results depending on the substitution sites. Recently, t he contributions of some stabilization factors have been quantitatively der ived as parameters by a unique equation, considering the conformational cha nges due to the mutations using mutant human lysozymes [Funahashi et al, (1 999) Protein Eng, 12, 841-850], To evaluate these parameters estimated from the mutant human lysozymes, stability-structure datasets for the mutant T4 lysozymes were selected. The stabilities for the mutant T4 lysozymes could be roughly estimated using these parameters. Notable differences between t he estimated and experimental stabilities were caused by the uncertainty in part of the structures due to some Arg and Lys residues fluctuating on the surface of the T4 lysozyme. Excluding these atoms from the estimation gave a good correlation between the estimated and experimental stabilities. The se results suggest that the parameters of the various stabilization factors derived from the mutant human lysozymes are compatible with the mutant T4 lysozymes, although they should be improved with respect to some points usi ng more information.