Title

Steady-State Kinetic Mechanism Of Loda, A Novel Cysteine Tryptophylquinone-Dependent Oxidase

Keywords

Amine oxidase; Cofactor; Lysine oxidase; Quinoprotein; Redox enzyme

Abstract

LodA is a novel lysine-ε-oxidase which possesses a cysteine tryptophylquinone cofactor. It is the first tryptophylquinone enzyme known to function as an oxidase. A steady-state kinetic analysis shows that LodA obeys a ping-pong kinetic mechanism with values of kcat of 0.22 ± 0.04 s-1, Klysine of 3.2 ± 0.5 μM and KO2 of 37.2 ± 6.1 μM. The kcat exhibited a pH optimum at 7.5 while kcat/Klysine peaked at 7.0 and remained constant to pH 8.5. Alternative electron acceptors could not effectively substitute for O2 in the reaction. A mechanism for the reductive half reaction of LodA is proposed that is consistent with the ping-pong kinetics. © 2014 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.

Publication Date

3-3-2014

Publication Title

FEBS Letters

Volume

588

Issue

5

Number of Pages

752-756

Document Type

Article

Personal Identifier

scopus

DOI Link

https://doi.org/10.1016/j.febslet.2014.01.021

Socpus ID

84896725520 (Scopus)

Source API URL

https://api.elsevier.com/content/abstract/scopus_id/84896725520

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