Publications

• L-tryptophan 2',3'-oxidase from Chromobacterium violaceum. Substrate specificity and mechanistic implications.

  Genet R., Benetti P.H., Hammadi A., Menez A.

  L-Tryptophan 2',3'-oxidase, an amino acid alpha,beta-dehydrogenase isolated from Chromobacterium violaceum, catalyzes the formation of a double bond between the C alpha and C beta carbons of various tryptophan derivatives provided that they possess: (i) a L-enantiomeric configuration, (ii) an alph ... >> More

  L-Tryptophan 2',3'-oxidase, an amino acid alpha,beta-dehydrogenase isolated from Chromobacterium violaceum, catalyzes the formation of a double bond between the C alpha and C beta carbons of various tryptophan derivatives provided that they possess: (i) a L-enantiomeric configuration, (ii) an alpha-carbonyl group, and (iii) an unsubstituted and unmodified indole nucleus. Kinetic parameters were evaluated for a series of tryptophan analogues, providing information on the contribution of each chemical group to substrate binding. The stereochemistry of the dehydro product was determined to be a Z-configuration from proton nuclear magnetic resonance assignments. No reaction can be observed in the presence of other aromatic beta-substituted alanyl residues which behave neither as substrates nor as inhibitors and therefore do not compete against this reaction. The enzymatic synthesis of alpha,beta-dehydrotryptophanyl peptides from 5 to 24 residues was successfully achieved without side product formation, irrespective of the position of the tryptophan residue in the amino acid sequence. A reactional mechanism involving a direct alpha,beta-dehydrogenation of the tryptophan side chain is proposed. << Less

  J Biol Chem 270:23540-23545(1995) [PubMed] [EuropePMC]

• Purification and partial characterization of an amino acid alpha,beta- dehydrogenase, L-tryptophan 2',3'-oxidase from Chromobacterium violaceum.

  Genet R., Denoyelle C., Menez A.

  L-Tryptophan 2',3'-oxidase is a novel enzyme that specifically catalyzes the alpha,beta-dehydrogenation of L-tryptophan derivatives. It was extracted from Chromobacterium violaceum and purified 108-fold to apparent homogeneity with a 34% overall recovery. The molecular weight of the native enzyme ... >> More

  L-Tryptophan 2',3'-oxidase is a novel enzyme that specifically catalyzes the alpha,beta-dehydrogenation of L-tryptophan derivatives. It was extracted from Chromobacterium violaceum and purified 108-fold to apparent homogeneity with a 34% overall recovery. The molecular weight of the native enzyme is approximately 680,000, and its isoelectric point is nearly equal to 4. SDS-polyacrylamide gel electrophoresis showed that the enzyme is composed of two components with molecular weight of approximately 74,000 and 14,000. It also contains a noncovalently bound heme prosthetic group, as judged from a typical spectrum showing maxima at 427, 530, and 560 nm. The catalyzed reaction is completed without side-product formation over a broad pH range comprised between 3 and 8. The enzyme is reoxidized at the expense of molecular oxygen by producing one molecule of H2O2. Kinetic parameters for modification of N-acetyl-L-tryptophanamide were determined (Km = 19.5 microM; kcat = 45.2 s-1). A Hill coefficient of about 1 suggests the absence of any cooperative effect. As inferred from both its kinetic and stability optimal conditions, L-tryptophan 2',3'-oxidase constitutes a promising tool for chemical modification of tryptophanyl side chain in peptides and proteins. << Less

  J Biol Chem 269:18177-18184(1994) [PubMed] [EuropePMC]