Quinoline oxidoreductase from Pseudomonas putida 86: an improved purification procedure and electron paramagnetic resonance spectroscopy.
Quinoline oxidoreductase, an iron-sulfur molybdenum flavoprotein containing flavin adenine dinucleotide and molybdopterin cytosine dinucleotide, was purified from Pseudomonas putida 86 to homogeneity. The various electron-transfer centers of the purified enzyme were examined by electron paramagnetic resonance spectroscopy. Quinoline deuterated at position 2 was prepared by deuterodecarboxylation of 2-quinolinecarboxylic acid. Quinoline added to the enzyme elicited the Mo(V) "rapid" type Q signal arising from the complex of enzyme and substrate, whereas in oxidized quinoline oxidoreductase a Mo(V) "resting" signal was observed. EPR spectroscopy at helium temperatures below 70 K revealed the existence of two types of iron-sulfur centers, Fe-S I and Fe-S II. An organic free radical appeared upon reduction with sodium dithionite. Inactivation of the enzyme by cyanide led to the inactive desulfo quinoline oxidoreductase, which yielded another Mo(V) signal designated "slow" type Q upon reduction with dithionite. Desulfo quinoline oxidoreductase was partially reactivated by incubation with sulfide.
Tshisuaka
B
B
Fachrichtung Biophysik und Physikalische Grundlagen der Medizin, Universität des Saarlandes, Germany.
Kappl
R
R
Hüttermann
J
J
Lingens
F
F
D003486:Cyanides / Q000494:pharmacology; D004578:Electron Spin Resonance Spectroscopy; D004793:Enzyme Reactivators / Q000494:pharmacology; D005609:Free Radicals; D007506:Iron-Sulfur Proteins / Q000737:chemistry* / Q000187:drug effects / Q000302:isolation & purification; D008982:Molybdenum / Q000737:chemistry; D010084:Oxidation-Reduction; D010088:Oxidoreductases / Q000737:chemistry* / Q000187:drug effects / Q000302:isolation & purification; D044925:Oxidoreductases Acting on CH-CH Group Donors; D016958:Pseudomonas putida / Q000201:enzymology* / Q000254:growth & development; D013440:Sulfides / Q000494:pharmacology
D003486:Cyanides; D004793:Enzyme Reactivators; D005609:Free Radicals; D007506:Iron-Sulfur Proteins; D013440:Sulfides; D008982:Molybdenum; D010088:Oxidoreductases; D044925:Oxidoreductases Acting on CH-CH Group Donors; C068667:quinoline 2-oxidoreductase; C033479:sodium sulfide