| First Author | Li W | Year | 2015 |
| Journal | Arch Biochem Biophys | Volume | 565 |
| Pages | 49-56 | PubMed ID | 25444857 |
| Mgi Jnum | J:230287 | Mgi Id | MGI:5755923 |
| Doi | 10.1016/j.abb.2014.11.004 | Citation | Li W, et al. (2015) Steady-state substrate specificity and O(2)-coupling efficiency of mouse cysteine dioxygenase. Arch Biochem Biophys 565:49-56 |
| abstractText | Cysteine dioxygenase (CDO) is a non-heme mononuclear iron enzyme that catalyzes the oxygen-dependent oxidation of L-cysteine (Cys) to produce L-cysteine sulfinic acid (CSA). Sequence alignment of mammalian CDO with recently discovered thiol dioxygenase enzymes suggests that the mononuclear iron site within all enzymes in this class share a common 3-His first coordination sphere. This implies a similar mechanistic paradigm among thiol dioxygenase enzymes. Although steady-state studies were first reported for mammalian CDO over 45 years ago, detailed analysis of the specificity for alternative thiol-bearing substrates and their oxidative coupling efficiencies have not been reported for this enzyme. Assuming a similar mechanistic theme among this class of enzymes, characterization of the CDO substrate specificity may provide valuable insight into substrate-active site intermolecular during thiol oxidation. In this work, the substrate-specificity for wild-type Mus musculus CDO was investigated using NMR spectroscopy and LC-MS for a variety of thiol-bearing substrates. Tandem mass spectrometry was used to confirm dioxygenase activity for each non-native substrate investigated. Steady-state Michaelis-Menten parameters for sulfinic acid product formation and O(2)-consumption were compared to establish the coupling efficiency for each reaction. In light of these results, the minimal substrate requirements for CDO catalysis and O(2)-activation are discussed. |
