Zeaxanthin epoxidase explained

Zeaxanthin epoxidase
Ec Number:	1.14.13.90
Cas Number:	149718-34-3

Zeaxanthin epoxidase (Zea-epoxidase) is an enzyme with systematic name zeaxanthin,NAD(P)H:oxygen oxidoreductase.^{[1] [2] [3] [4] [5] [6] [7]} This enzyme catalyses the following chemical reaction

zeaxanthin + 2 NAD(P)H + 2 H⁺ + 2 O₂

\rightleftharpoons violaxanthin + 2 NAD(P)⁺ + 2 H₂O (overall reaction)

(1a) zeaxanthin + NAD(P)H + H⁺ + O₂

\rightleftharpoons antheraxanthin + NAD(P)⁺ + H₂O

(1b) antheraxanthin + NAD(P)H + H⁺ + O₂

\rightleftharpoons violaxanthin + NAD(P)⁺ + H₂O

Zeaxanthin epoxidase is a flavoprotein (FAD) that is active under conditions of low light.

Notes and References

1. Büch K, Stransky H, Hager A . FAD is a further essential cofactor of the NAD(P)H and O2-dependent zeaxanthin-epoxidase . FEBS Letters . 376 . 1–2 . 45–8 . November 1995 . 8521963 . 10.1016/0014-5793(95)01243-9 . free .
2. Bugos RC, Hieber AD, Yamamoto HY . Xanthophyll cycle enzymes are members of the lipocalin family, the first identified from plants . The Journal of Biological Chemistry . 273 . 25 . 15321–4 . June 1998 . 9624110 . 10.1074/jbc.273.25.15321 . free .
3. Thompson AJ, Jackson AC, Parker RA, Morpeth DR, Burbidge A, Taylor IB . Abscisic acid biosynthesis in tomato: regulation of zeaxanthin epoxidase and 9-cis-epoxycarotenoid dioxygenase mRNAs by light/dark cycles, water stress and abscisic acid . Plant Molecular Biology . 42 . 6 . 833–45 . April 2000 . 10890531 . 10.1023/A:1006448428401 .
4. Hieber AD, Bugos RC, Yamamoto HY . Plant lipocalins: violaxanthin de-epoxidase and zeaxanthin epoxidase . Biochimica et Biophysica Acta (BBA) - Protein Structure and Molecular Enzymology . 1482 . 1–2 . 84–91 . October 2000 . 11058750 . 10.1016/s0167-4838(00)00141-2 .
5. Frommolt R, Goss R, Wilhelm C . The de-epoxidase and epoxidase reactions of Mantoniella squamata (Prasinophyceae) exhibit different substrate-specific reaction kinetics compared to spinach . Planta . 213 . 3 . 446–56 . July 2001 . 11506368 . 10.1007/s004250100589 .
6. Erratum Report. The de-epoxidase and epoxidase reactions of Mantoniella squamata (Prasinophyceae) exhibit different substrate-specific reaction kinetics compared to spinach . Frommolt R, Goss R, Wilhelm C . Planta . 2001 . 213 . 492 . 10.1007/s004250100619 . 3.
7. Matsubara S, Morosinotto T, Bassi R, Christian AL, Fischer-Schliebs E, Lüttge U, Orthen B, Franco AC, Scarano FR, Förster B, Pogson BJ, Osmond CB . Occurrence of the lutein-epoxide cycle in mistletoes of the Loranthaceae and Viscaceae . Planta . 217 . 6 . 868–79 . October 2003 . 12844265 . 10.1007/s00425-003-1059-7 .