Reactivity of 3-HBA-6-hydroxylase with diethylpyrocarbonate and N-bromosuccinimide: Effect of chemical modifications on kinetic and spectral properties of the enzyme

Sumathi, S and Dasgupta, D (2000) Reactivity of 3-HBA-6-hydroxylase with diethylpyrocarbonate and N-bromosuccinimide: Effect of chemical modifications on kinetic and spectral properties of the enzyme. In: Biotechnology Progress, 16 (04). pp. 577-582.

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Abstract

The rapid inactivation of 3-HBA-6-hydroxylase by 100 mu M diethylpyrocarbonate or 40 mu M N-bromosuccinimide and protection offered by the substrate, 3-hydroxybenzoate, against these chemical modifications implicate the involvement of histidine and tryptophan in the catalytic activity of the enzyme. Inactivation of the enzyme by diethylpyrocarbonate followed pseudo-first-order kinetics, and an "n" value of 1.3 was obtained. Inactivation of the enzyme by N-bromosuccinimide was instantaneous and failed to follow pseudo-first-order kinetics. Distinct and incremental changes in the UV absorption, emission fluorescence, and near UV-CD spectra of the enzyme upon its titration with increasing concentrations of diethylpyrocarbonate or N-bromosuccinimide may be ascribed to modification and/or changes in the microenvironment of aromatic amino acid residue(s) such as tryptophan in the enzyme.

Item Type:	Journal Article
Publication:	Biotechnology Progress
Publisher:	John Wiley and Sons
Additional Information:	Copyright of this article belongs to American Chemical Society.
Department/Centre:	Division of Biological Sciences > Biochemistry
Date Deposited:	20 Nov 2009 09:00
Last Modified:	19 Sep 2010 05:24
URI:	http://eprints.iisc.ac.in/id/eprint/18638

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