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Journal article

Structure of ACC synthase inactivated by the mechanism-based inhibitor L-vinylglycine.

  • 2005-04-26
Published in:
  • FEBS letters. - 2005
Crystallography, X-Ray
Enzyme Inhibitors
Glycine
Lyases
Malus
Models, Molecular
Molecular Structure
Protein Structure, Tertiary
Pyridoxal Phosphate
Substrate Specificity
English L-Vinylglycine (L-VG) is both a substrate for and a mechanism-based inhibitor of 1-aminocyclopropane-1-carboxylate (ACC) synthase. The ratio of the rate constants for catalytic conversion to alpha-ketobutyrate and ammonia to inactivation is 500/1. The crystal structure of the covalent adduct of the inactivated enzyme was determined at 2.25 Angstroms resolution. The active site contains an external aldimine of the adduct of L-VG with the pyridoxal 5'-phosphate cofactor. The side chain gamma-carbon of L-VG is covalently bound to the epsilon-amino group of Lys273. This species corresponds to one of the two alternatives proposed by Feng and Kirsch [Feng, L. and Kirsch, J.F. (2000) L-Vinylglycine is an alternative substrate as well as a mechanism-based inhibitor of 1-aminocyclopropane-1-carboxylate synthase. Biochemistry 39, 2436-2444] and presumably results from Michael addition to a vinylglycine ketimine intermediate.
Language
  • English
Open access status
bronze
Identifiers
Persistent URL
https://folia.unifr.ch/global/documents/210648
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