Comparison of inactivation and unfolding of methanol dehydrogenase during denaturation in guanidine hydrochloride and urea
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Updated: Oct 13, 2026

Detection of the pH-dependent Activity of Escherichia coli Chaperone HdeB In Vitro and In Vivo
Published on: October 23, 2016
1Department of Biochemistry and Biophysics, College of Life Sciences, Wuhan University, People's Republic of China.
Abstract:
The activity and the conformational changes of methanol dehydrogenase (MDH), a quinoprotein containing pyrrolo-quinoline quinone as its prosthetic group, have been studied during denaturation in guanidine hydrochloride (GdnHCl) and urea. The unfolding of MDH was followed using the steady-state and time resolved fluorescence methods. Increasing the denaturant concentration in the denatured system significantly enhanced the inactivation and unfolding of MDH. The enzyme was completely inactivated at 1 M GdnHCl or 6 M urea. The fluorescence emission maximum of the native enzyme was at 332 nm. With increasing denaturant concentrations, the fluorescence emission maximum red-shifted in magnitude to a maximum value (355 nm) at 5 M GdnHCl or 8 M urea. Comparison of inactivation and conformational changes during denaturation showed that in general accord with the suggestion made previously by Tsou, the active sites of MDH are situated in a region more flexible than the molecule as a whole.
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