Enzyme Quinoline-2-oxidoreductase

Bauder R, B Tshisuaka, F Lingens (1990) Microbial metabolism of quinoline and related compounds VII. Quinoline oxidoreductase from Pseudomonas putida a molybdenum-containing enzyme. Biol Chem Hoppe-Seyler 371 1137-1144. 

Schach S, B Tshisuaka, S Fetzner, F Lingens F (1995) Quinoline 2-oxidoreductase and 2-oxo-l,2-dihydro-quinoline 5,6-dioxygenase from Comamonas testosteroni 63. The first two enzymes in quinoline and 3-methylquinoline degradation. EurJ Biochem 232 536-544. 

The enzymes from Comamonas testosteroni for hydroxylation of quinoline to quinol-2-one (quinoline 2-oxidoreductase) and the dioxygenase responsible for the introduction of oxygen into the benzenoid ring (2-oxo-l,2-dihydroquinoline 5,6-dioxygenase) have been described (Schach et al. 1995). 

De Beyer A, E Lingens (1993) Microbial metabolism of quinoline and related compounds XVI. Quinaldine oxidoreductase from Arthrobacter spec. Rii 61a a molybdenum-containing enzyme catalysing the hydroxylation at C-4 of the heterocycle. Biol Chem Eloppe-Seyler 374 101-120. 

Canne and co-workers have presented EPR studies of three prokaryotic enzymes of the xanthine oxidase family, namely quinoline 2-oxidoreductase, quinaldine 4-oxidase, and isoquinoline l-oxidoreductaseJ In quinoline 2-oxidoreductase a neutral flavin radical was observed, while in quinaldine 4-oxidase an anionic radical was detected. The rapid Mo(V) signal was observed in all three enzymes with only small differences in magnetic parameters. From spectra simulations of Mo (/ = 5/2) substituted quinoline 2-oxidoreductase, a deviation of 25° between the maximal g and Mo-hfc tensor component was derived. The Mo(V) species was detected in small amounts upon reduction with substrates in quinoline 2-oxidoreductase and quinaldine 4-oxidase, but showed a different kinetic behaviour with an intense EPR signal in isoquinoline 1-oxidoreductase. The two [2Fe-2S] clusters produced different EPR signals in all three enzymes and, in isoquinoline 1-oxidoreductase, revealed a dipolar interaction, from which a maximum distance of 15 A was estimated. 

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