Quinone compounds are able to replace molecular oxygen as terminal electron acceptor in phytoene desaturation in chromoplasts of Narcissus pseudonarcissus L.
The desaturation of phytoene to zeta-carotene and of zeta-carotene to lycopene employs molecular oxygen as the terminal electron acceptor. 2,3,5,6-Tetramethyl-1,4-benzoquinone (duroquinone) and other artificial quinones are able to replace oxygen, which demonstrates that oxygen does not act in a mixed-function oxygenase-like mechanism at the desaturase itself, but at a spatially separate site. Evidence for additional redox elements mediating between desaturase and oxygen is presented.
Mayer
M P
MP
Institut für Biologie II, Universität Freiburg, Federal Republic of Germany.
Beyer
P
P
Kleinig
H
H
D002338:Carotenoids / Q000378:metabolism*; D004579:Electron Transport; D010084:Oxidation-Reduction; D010088:Oxidoreductases / Q000378:metabolism*; D010100:Oxygen / Q000378:metabolism*; D010944:Plants / Q000201:enzymology / Q000378:metabolism*; D011809:Quinones / Q000378:metabolism*
D011809:Quinones; D002338:Carotenoids; C100185:(all-E) phytoene; D010088:Oxidoreductases; C022398:phytoene dehydrogenase; D010100:Oxygen