Steady-state kinetic mechanism of LodA, a novel cysteine tryptophylquinone-dependent oxidase

    Authors

    E. Sehanobish; S. Shin; A. Sanchez-Amat;V. L. Davidson

    Comments

    Authors: contact us about adding a copy of your work at [email protected]

    Abbreviated Journal Title

    FEBS Lett.

    Keywords

    Amine oxidase; Cofactor; Quinoprotein; Lysine oxidase; Redox enzyme; QUINOHEMOPROTEIN AMINE DEHYDROGENASE; PROTEIN LYSINE OXIDASE; MARINOMONAS-MEDITERRANEA; PARACOCCUS-DENITRIFICANS; LYSYL OXIDASE; TRYPTOPHAN TRYPTOPHYLQUINONE; METHYLAMINE DEHYDROGENASE; EPSILON-OXIDASE; COFACTOR; PURIFICATION; Biochemistry & Molecular Biology; Biophysics; Cell Biology

    Abstract

    LodA is a novel lysine-epsilon-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 k(cat) of 0.22 +/- 0.04 s (1), K-lysine of 3.2 +/- 0.5 mu M and K-O2 of 37.2 +/- 6.1 mu M. The k(cat) exhibited a pH optimum at 7.5 while k(cat)/K-lysine peaked at 7.0 and remained constant to pH 8.5. Alternative electron acceptors could not effectively substitute for O-2 in the reaction. A mechanism for the reductive half reaction of LodA is proposed that is consistent with the ping-pong kinetics. (C) 2014 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.

    Journal Title

    Febs Letters

    Volume

    588

    Issue/Number

    5

    Publication Date

    1-1-2014

    Document Type

    Article

    Language

    English

    First Page

    752

    Last Page

    756

    WOS Identifier

    WOS:000331717500017

    ISSN

    0014-5793

    Share

    COinS
     

    Accessibility Statement

    This item was created or digitized prior to April 24, 2027, or is a reproduction of legacy media created before that date. It is preserved in its original, unmodified state specifically for research, reference, or historical recordkeeping. In accordance with the ADA Title II Final Rule, the University Libraries provides accessible versions of archival materials upon request. To request an accommodation for this item, please submit an accessibility request form.