The unfolding of cytoplasmic aspartate aminotransferase from pig heart in solutions of guanidinium chloride (GdnHCl) was studied. Data from protein fluorescence, c.d. and thiol-group reactivity indicated that the enzyme was unfolded in 6 M-GdnHCl. Spectroscopic studies showed that this unfolding was accompanied by dissociation of the pyridoxal 5'-phosphate cofactor. On dilution of the GdnHCl, r...

The stability to pH and denaturing agents of crystalline leutine aminopeptidase (bovine lens) (EC 3.4.1.1) is reported. The native enzyme exhibited a molecular weight of 327,000. In 7 M urea below pH 3 and in 23.7 M guanidinium chloride below pH 8.5, both leucine aminopeptidase and its reduced and carboxamidomethylated derivative exhibited a molecular weight on equilibrium centrifugation of 54,...

We report the characterization of the first chaperonin (Mm-cpn) from a mesophilic archaeon, Methanococcus maripaludis. The single gene was cloned from genomic DNA and expressed in Escherichia coli to produce a recombinant protein of 543 amino acids. In contrast with other known archaeal chaperonins, Mm-cpn is fully functional in all respects under physiological conditions of 37 degrees C. The c...

The stability to pH and denaturing agents of crystalline leutine aminopeptidase (bovine lens) (EC 3.4.1.1) is reported. The native enzyme exhibited a molecular weight of 327,000. In 7 M urea below pH 3 and in 23.7 M guanidinium chloride below pH 8.5, both leucine aminopeptidase and its reduced and carboxamidomethylated derivative exhibited a molecular weight on equilibrium centrifugation of 54,...