3-Hydroxy-β-ionone, a flavor and fragrance compound with fruity violet-like characteristics, is widely applied in foodstuff beverages, currently produced using synthetic chemistry. In this study, novel lutein cleavage enzyme (EhLCD) was purified characterized from Enterobacter hormaechei YT-3 to convert 3-hydroxy-β-ionone. Enzyme EhLCD homogeneity by ammonium sulfate precipitation, Q-Sepharose,...

Abstract AIMS The kynurenine (Kyn) pathway plays an important role in the pathogenesis of many cancers including glioblastomas (GBMs). enzymes, indoleamine-2,3-dioxygenase (IDO1) and tryptophan-2,3-dioxygenase (TDO2), regulate first rate-limiting step resulting formation N-formyl-kynurenine, which is then readily converted into Kyn by formaldehyde. Cancers expressing IDO1 TDO2 enzymes can produ...

Mycobacterium vanbaalenii PYR-1 is able to metabolize a wide range of low- and high-molecular-weight (HMW) polycyclic aromatic hydrocarbons (PAHs). A 20-kDa protein was upregulated in PAH-metabolizing M. vanbaalenii PYR-1 cells compared to control cultures. The differentially expressed protein was identified as a beta subunit of the terminal dioxygenase using mass spectrometry. PCR with degener...

Tryptophan 2,3-dioxygenase [L-tryptophan--oxygen 2,3-oxidoreductase (decyclizing), EC 1.13.11.11] has been reported to act solely on the L-isomer of tryptophan. However, by using a sensitive assay method with D- and L-[ring-2-14C]tryptophan and improved assay conditions, we were able to demonstrate that both the D- and L-stereoisomers of tryptophan were cleaved by the supernatant fraction (3000...

A protein fraction exhibiting 1-hydroxy-2-naphthoic acid (1-H2NA) dioxygenase activity was purified via ion exchange, hydrophobic interactions, and gel filtration chromatography from Arthrobacter phenanthrenivorans sp. nov. strain Sphe3 isolated from a Greek creosote-oil-polluted site. Matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) and tandem MS (MS-...

4-Nitrocatechol is examined as an active site probe for non-heme iron dioxygenases and found to be of value, particularly with those containing iron in the Fe(II) oxidation state. 4-Nitrocatechol is astrong competitive inhibitor of substrate oxygenation by protocatechuate 3,4-dioxygenase, forming a reversible complex with this enzyme, and by pyrocatechase. The number of binding sites per enzyme...

Pseudomonas sp. strain U2 was isolated from oil-contaminated soil in Venezuela by selective enrichment on naphthalene as the sole carbon source. The genes for naphthalene dioxygenase were cloned from the plasmid DNA of strain U2 on an 8.3-kb BamHI fragment. The genes for the naphthalene dioxygenase genes nagAa (for ferredoxin reductase), nagAb (for ferredoxin), and nagAc and nagAd (for the larg...