Characterization of reactivation produces from human carbonic anhydrase I denatured in various concentrations of guanidine hydrochloride.

Denaturation in 1.7 M guanidine hydrochloride (Gnd-HCl), thermostability tests, immunological tests and polyacrylamide-gel electrophoresis were performed on the products of reactivation from human carbonic anhydrase I (CA I), initially denatured in various concentrations of Gnd-HCl. Reactivated protein from CA I denatured in 2 M Gnd-HCl exhibited different thermostability and immunological properties from the products of other Gnd-HCl concentrations. The CA I denatured in 2 M Gnd-HCl was found to be more heat stable and achieved complete inhibition at an antibody concentration one-fourth that of the other Gnd-HCl denaturation concentrations. These data suggest that 2 M Gnd-HCl produces a reactivation product with a different tertiary structure from 5 M or 0.5 M Gnd-HCl.