Related Experiment Video
Updated: Sep 26, 2026

An Assay for Measuring the Activity of Escherichia coli Inducible Lysine Decarboxyase
Published on: December 19, 2010
Studies on structure-function relationships of indolepyruvate decarboxylase from Enterobacter cloacae, a key enzyme
Anja Schütz1, Ralph Golbik, Kai Tittmann
1Institut für Biochemie, Fachbereich Biochemie/Biotechnologie, Martin-Luther-Universität Halle-Wittenberg, Halle, Germany.
Abstract:
Enterobacter cloacae, isolated from the rhizosphere of cucumbers, produces large amounts of indole-3-acetic acid. Indolepyruvate decarboxylase, the key enzyme in the biosynthetic pathway of indole-3-acetic acid, catalyses the formation of indole-3-acetaldehyde and carbon dioxide from indole-3-pyruvic acid. The enzyme requires the cofactors thiamine diphosphate and magnesium ions for catalytic activity. Recombinant indolepyruvate decarboxylase was purified from the host Escherichia coli strain JM109. Specificity of the enzyme for the substrates indole-3-pyruvic acid, pyruvic acid, benzoylformic acid, and seven benzoylformic acid analogues was investigated using a continuous optical assay. Stopped-flow kinetic data showed no indication for substrate activation in the decarboxylation reaction of indole-3-pyruvic acid, pyruvic acid or benzoylformic acid. Size exclusion chromatography and small angle X-ray solution scattering experiments suggested the tetramer as the catalytically active state and a pH-dependent subunit association equilibrium. Analysis of the kinetic constants of the benzoylformic acid analogues according to Hansch et al. [Hansch, C., Leo, A., Unger, S.H., Kim, K.H., Nikaitani, D & Lien, E.J. (1973) J. Med. Chem.16, 1207-1216] and comparison with indole-3-pyruvic acid conversion by pyruvate decarboxylases from Saccharomyces cerevisiae and Zymomonas mobilis provided some insight into the catalytic mechanism of indolepyruvate decarboxylase.
More Related Videos
09:27Functional Complementation Analysis (FCA): A Laboratory Exercise Designed and Implemented to Supplement the Teaching of Biochemical Pathways
Published on: June 24, 2016
08:31Anaerobic Protein Purification and Kinetic Analysis via Oxygen Electrode for Studying DesB Dioxygenase Activity and Inhibition
Published on: October 3, 2018
Related Concept Videos
E1 Reaction: Kinetics and Mechanism
E2 Reaction: Kinetics and Mechanism
Phase II Reactions: Acetylation Reactions
The substrates for acetylation are typically drugs or their metabolites with an amino, sulfonamide, or hydrazine functional group. Acetylation can occur at several points in the drug molecule, including primary, secondary, and...
Regioselective Formation of Enolates
Inducible Operons: lac Operon
Amino Acid Biosynthetic Pathways