Analysis of the role of the active site residue Arg98 in the flavoprotein tryptophan 2-monooxygenase, a member of the L-amino oxidase family.

ABSTRACT: The flavoprotein tryptophan 2-monooxygenase catalyzes the oxidative decarboxylation of tryptophan to indoleacetamide. We have previously identified tryptophan 2-monooxygenase as a homologue of L-amino acid oxidase [Sobrado, P., and Fitzpatrick, P. F. (2002) Arch. Biochem. Biophys. 402, 24-30]. On the basis of the sequence comparisons of the different LAAO family members, Arg98 of tryptophan 2-monooxygenase can be identified as an active site residue which interacts with the carboxylate of the amino acid substrate. The catalytic properties of R98K and R98A tryptophan 2-monooxygenase have been characterized to evaluate the role of this residue. Mutation of Arg98 to lysine decreases the first-order rate constant for flavin reduction by 180-fold and the second-order rate constant for flavin ox

SUBMITTER: Sobrado P 

PROVIDER: S-EPMC1635017 | biostudies-literature | 2003 Dec

REPOSITORIES: biostudies-literature