Guanidine Hydrochloride Unfolding of a Carbonic Anhydrase Molten Globule

Guanidine hydrochloride-induced unfolding of a carbonic anhydrase molten globule was studied by high-resolution nuclear magnetic resonance spectroscopy. The study resulted in estimation of the number of water and denaturant molecules bound to the molten globule at various denaturant concentrations in solution. When compared with the data on unfolding of native carbonic anhydrase, these estimates indicate that the unfolding is underlain by an increased local concentration of the denaturant near the protein molecule, which results from the increased ratio between guanidine hydrochloride-bound and protein-bound waters.