Characterization of Reactivation Products from Human Carbonic Anhydrase I Denatured in Various Concentrations of Guanidine Hydrochloride

Abstract

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.