Thermal and conformational stability of Ssh10b protein from archaeon Sulfolobus shibattae.

ABSTRACT: The secondary structure of the DNA binding protein Ssh10b is largely unaffected by change in temperature between 25 degrees C and 85 degrees C, indicating that the protein is highly thermostable. Here, we report the temperature-dependent equilibrium denaturation of Ssh10b in the presence of guanidine hydrochloride (GdnHCl). It was found that the transition midpoint values of the temperature (T(m)), and changes of enthalpy (DeltaH(m)) and entropy (DeltaS(m)) of Ssh10b unfolding were linearly decreasing with increasing GdnHCl concentration. The true values of the thermodynamic parameters, T(m)=402 K, DeltaH(m)=590+/-40 kJ x mol(-1) and DeltaS(m)=1.4+/-0.15 kJ x T(-1) x mol(-1), were obtained by linear extrapolation to 0 M GdnHCl. The value of the heat capacity change of Ssh10b unfolding, Del

SUBMITTER: Xu S 

PROVIDER: S-EPMC1182282 | biostudies-literature | 2004 Sep

REPOSITORIES: biostudies-literature