Two-dimensional IR correlation spectroscopy of mutants of the beta-glycosidase from the hyperthermophilic archaeon Sulfolobus solfataricus identifies the mechanism of quaternary structure stabilization and unravels the sequence of thermal unfolding events.

ABSTRACT: Beta-glycosidase from the hyperthermophilic archaeon Sulfolobus solfataricus is a homotetramer with a higher number of ion pairs compared with mesophilic glycoside hydrolases. The ion pairs are arranged in large networks located mainly at the tetrameric interface of the molecule. In the present study, the structure and thermal stability of the wild-type beta-glycosidase and of three mutants in residues R488 and H489 involved in the C-terminal ionic network were examined by FTIR (Fourier-transform IR) spectroscopy. The FTIR data revealed small differences in the secondary structure of the proteins and showed a lower thermostability of the mutant proteins with respect to the wild-type. Generalized 2D-IR (two-dimensional IR correlation spectroscopy) at different temperatures showed different

SUBMITTER: Ausili A 

PROVIDER: S-EPMC1134089 | biostudies-literature | 2004 Nov

REPOSITORIES: biostudies-literature