STABILITY AND DYNAMICS IN A HYPERTHERMOPHILIC PROTEIN WITH MELTING TEMPERATURE CLOSE TO 200-DEGREES-C

The rubredoxin protein from the hyperthermophilic archaebacterium Pyro coccus furiosus was examined by a hydrogen exchange method, Even thoug h the protein does not exhibit reversible thermal unfolding, one can d etermine its stability parameters-free energy, enthalpy, entropy, and melting temperature-and also the distribution of stability throughout the protein, by using hydrogen exchange to measure the reversible cycl ing of the protein between native and unfolded states that occurs even under native conditions.