1.23.5.1: violaxanthin de-epoxidase
This is an abbreviated version!
For detailed information about violaxanthin de-epoxidase, go to the full flat file.
Word Map on EC 1.23.5.1
-
1.23.5.1
-
vertical
-
xanthophyll
-
zeaxanthin
-
thylakoids
-
photoelectron
-
de-epoxidation
-
photosystem
-
photoprotection
-
non-photochemical
-
adiabatic
-
antheraxanthin
-
photoinhibition
-
ccsdt
-
coupled-cluster
-
monogalactosyldiacylglycerol
-
barrier-free
-
photodetachment
-
lowest-energy
-
diadinoxanthin
-
pi-scei
-
transthylakoid
-
deepoxidase
- 1.23.5.1
-
vertical
-
xanthophyll
- zeaxanthin
- thylakoids
-
photoelectron
-
de-epoxidation
-
photosystem
-
photoprotection
-
non-photochemical
-
adiabatic
- antheraxanthin
-
photoinhibition
-
ccsdt
-
coupled-cluster
- monogalactosyldiacylglycerol
-
barrier-free
-
photodetachment
-
lowest-energy
- diadinoxanthin
-
pi-scei
-
transthylakoid
-
deepoxidase
Reaction
Synonyms
AhVDE, CsVDE, EC 1.10.99.3, lipocalin-like protein, NPQ1, VDE, Vio de-epoxidase, violaxanthin de-epoxidase, Vx de-epoxidase, ZmVDE1
ECTree
1.23.5.1 violaxanthin de-epoxidaseAdvanced search results
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results (Substrates Products
Substrates Products on EC 1.23.5.1 - violaxanthin de-epoxidase
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SUBSTRATE 
PRODUCT
REACTION DIAGRAM
ORGANISM
UNIPROT
COMMENTARY
(Substrate)
(Substrate)
LITERATURE
(Substrate)
(Substrate)
COMMENTARY
(Product)
(Product)
LITERATURE
(Product)
(Product)
Reversibility
r=reversible
ir=irreversible
?=not specified
r=reversible
ir=irreversible
?=not specified
cryptoxanthin epoxide + ascorbate
?
-
92% of the activity with violaxanthin
-
-
?
diadinoxanthin + ascorbate
?
-
the activity is 2.25fold higher than the activity of violaxanthin
-
-
?
lutein epoxide + ascorbate
?
-
the activity is 1.33fold higher than the activity of violaxanthin
-
-
?
all-trans-neoxanthin + ascorbate
? + dehydroascorbate + H2O
-
0.21% of the activity with violaxanthin
-
-
?
all-trans-neoxanthin + ascorbate
? + dehydroascorbate + H2O
-
2.5% of the activity with violaxanthin
-
-
?
antheraxanthin + ascorbate
zeaxanthin + dehydroascorbate + H2O
-
-
-
-
?
antheraxanthin + ascorbate
zeaxanthin + dehydroascorbate + H2O
-
-
-
?
antheraxanthin + ascorbate
zeaxanthin + dehydroascorbate + H2O
violaxanthin de-epoxidase and zeaxanthin epoxidase catalyze the addition and removal of epoxide groups in carotenoids of xanthophyll cycle in plants. The xanthophyll cycle is implicated in protecting the photosynthetoic apparatus from excessive light
-
-
?
antheraxanthin + ascorbate
zeaxanthin + dehydroascorbate + H2O
-
the activity is 5.25fold higher than the activity of violaxanthin
-
-
?
antheraxanthin + ascorbate
zeaxanthin + dehydroascorbate + H2O
-
the violaxanthin/antheraxanthin cycle in Mantionella is caused by the interaction of the slow second de-epoxidation step and the relatively fast epoxidation of antheraxanthin to violaxanthin
-
-
?
antheraxanthin + ascorbate
zeaxanthin + dehydroascorbate + H2O
-
11% of the activity with violaxanthin
-
-
?
antheraxanthin + ascorbate
zeaxanthin + dehydroascorbate + H2O
violaxanthin de-epoxidase and zeaxanthin epoxidase catalyze the addition and removal of epoxide groups in carotenoids of xanthophyll cycle in plants. The xanthophyll cycle is implicated in protecting the photosynthetoic apparatus from excessive light
-
-
?
antheraxanthin + ascorbate
zeaxanthin + dehydroascorbate + H2O
-
-
-
?
antheraxanthin + ascorbate
zeaxanthin + dehydroascorbate + H2O
-
de-epoxidation reaction of the xanthophyll cycle plays an important role in the protection of the chloroplast against photooxidative damage. Violaxanthin is bound to the antenna proteins of both photosystems. In photosystem II, the formation of zeaxanthin is essential for the pH-dependent dissipation of excess light energy as heat. Violaxanthin bound to site V1 and N1 is easily accessible for de-epoxidation, whereas violaxanthin bound to L2 is only partially and/or with the slower kinetics converible to zeaxanthin
-
-
?
antheraxanthin + ascorbate
zeaxanthin + dehydroascorbate + H2O
-
-
-
-
?
antheraxanthin + ascorbate
zeaxanthin + dehydroascorbate + H2O
-
146% of the activity with violaxanthin
-
-
?
antheraxanthin + ascorbate
zeaxanthin + dehydroascorbate + H2O
-
-
-
-
?
antheraxanthin + ascorbate
zeaxanthin + dehydroascorbate + H2O
-
reaction of the xanthophyll cycle
-
-
?
antheraxanthin + L-ascorbate
zeaxanthin + L-dehydroascorbate + H2O
-
-
-
-
?
antheraxanthin + L-ascorbate
zeaxanthin + L-dehydroascorbate + H2O
-
-
-
?
antheraxanthin + L-ascorbate
zeaxanthin + L-dehydroascorbate + H2O
-
-
-
-
?
antheraxanthin + L-ascorbate
zeaxanthin + L-dehydroascorbate + H2O
-
-
-
-
?
antheraxanthin + L-ascorbate
zeaxanthin + L-dehydroascorbate + H2O
-
-
-
?
antheraxanthin + L-ascorbate
zeaxanthin + L-dehydroascorbate + H2O
-
-
-
?
antheraxanthin + L-ascorbate
zeaxanthin + L-dehydroascorbate + H2O
-
-
-
-
?
cryptoxanthin-5,6,5',6'-di-epoxide + ascorbate
? + dehydroascorbate + H2O
-
36.5% of the activity with violaxanthin
-
-
?
cryptoxanthin-5,6,5',6'-di-epoxide + ascorbate
? + dehydroascorbate + H2O
-
54% of the activity with violaxanthin
-
-
?
cryptoxanthin-5,6-epoxide + ascorbate
? + dehydroascorbate + H2O
-
1% of the activity with violaxanthin
-
-
?
cryptoxanthin-5,6-epoxide + ascorbate
? + dehydroascorbate + H2O
-
12.5% of the activity with violaxanthin
-
-
?
diadinoxanthin + ascorbate
? + dehydroascorbate + H2O
-
11% of the activity with violaxanthin
-
-
?
diadinoxanthin + ascorbate
? + dehydroascorbate + H2O
-
69% of the activity with violaxanthin
-
-
?
lutein-5,6-epoxide + ascorbate
? + dehydroascorbate + H2O
-
20% of the activity with violaxanthin
-
-
?
lutein-5,6-epoxide + ascorbate
? + dehydroascorbate + H2O
-
110% of the activity with violaxanthin
-
-
?
violaxanthin + 2 L-ascorbate
zeaxanthin + 2 L-dehydroascorbate + 2 H2O
-
-
-
-
?
violaxanthin + 2 L-ascorbate
zeaxanthin + 2 L-dehydroascorbate + 2 H2O
overall reaction
-
-
?
violaxanthin + 2 L-ascorbate
zeaxanthin + 2 L-dehydroascorbate + 2 H2O
overall reaction
-
-
?
violaxanthin + 2 L-ascorbate
zeaxanthin + 2 L-dehydroascorbate + 2 H2O
overall reaction
-
-
?
violaxanthin + 2 L-ascorbate
zeaxanthin + 2 L-dehydroascorbate + 2 H2O
overall reaction
-
-
?
violaxanthin + ascorbate
antheraxanthin + dehydroascorbate + H2O
-
-
-
-
?
violaxanthin + ascorbate
antheraxanthin + dehydroascorbate + H2O
-
-
-
?
violaxanthin + ascorbate
antheraxanthin + dehydroascorbate + H2O
violaxanthin de-epoxidase and zeaxanthin epoxidase catalyze the addition and removal of epoxide groups in carotenoids of xanthophyll cycle in plants. The xanthophyll cycle is implicated in protecting the photosynthetic apparatus from excessive light
-
-
?
violaxanthin + ascorbate
antheraxanthin + dehydroascorbate + H2O
-
-
-
-
?
violaxanthin + ascorbate
antheraxanthin + dehydroascorbate + H2O
-
-
-
-
?
violaxanthin + ascorbate
antheraxanthin + dehydroascorbate + H2O
-
-
-
-
?
violaxanthin + ascorbate
antheraxanthin + dehydroascorbate + H2O
violaxanthin de-epoxidase and zeaxanthin epoxidase catalyze the addition and removal of epoxide groups in carotenoids of xanthophyll cycle in plants. The xanthophyll cycle is implicated in protecting the photosynthetic apparatus from excessive light
-
-
?
violaxanthin + ascorbate
antheraxanthin + dehydroascorbate + H2O
-
-
-
-
?
violaxanthin + ascorbate
antheraxanthin + dehydroascorbate + H2O
-
-
-
?
violaxanthin + ascorbate
antheraxanthin + dehydroascorbate + H2O
-
de-epoxidation reaction of the xanthophyll cycle plays an important role in the protection of the chloroplast against photooxidative damage. Violaxanthin is bound to the antenna proteins of both photosystems. In photosystem II, the formation of zeaxanthin is essential for the pH-dependent dissipation of excess light energy as heat. Violaxanthin bound to site V1 and N1 is easily accessible for de-epoxidation, whereas violaxanthin bound to L2 is only partially and/or with the slower kinetics converible to zeaxanthin
-
-
?
violaxanthin + ascorbate
antheraxanthin + dehydroascorbate + H2O
-
-
-
-
?
violaxanthin + ascorbate
antheraxanthin + dehydroascorbate + H2O
-
-
-
-
?
violaxanthin + ascorbate
antheraxanthin + dehydroascorbate + H2O
-
reaction of the xanthophyll cycle
-
-
?
violaxanthin + L-ascorbate
antheraxanthin + L-dehydroascorbate + H2O
-
-
-
?
violaxanthin + L-ascorbate
antheraxanthin + L-dehydroascorbate + H2O
-
-
-
-
?
violaxanthin + L-ascorbate
antheraxanthin + L-dehydroascorbate + H2O
-
-
-
-
?
violaxanthin + L-ascorbate
antheraxanthin + L-dehydroascorbate + H2O
-
-
-
-
?
violaxanthin + L-ascorbate
antheraxanthin + L-dehydroascorbate + H2O
-
-
-
?
violaxanthin + L-ascorbate
antheraxanthin + L-dehydroascorbate + H2O
-
-
-
?
violaxanthin + L-ascorbate
antheraxanthin + L-dehydroascorbate + H2O
-
-
-
-
?
additional information
?
-
-
VDE is the first described putative plant lipocalin
-
-
?
additional information
?
-
-
the enzyme is inactive against monoepoxy and diepoxy beta-carotene, antheraxanthin-A and lutein epoxide
-
-
?
additional information
?
-
-
no activity with 9-cis neoxanthin and 9-cis violaxanthin
-
-
?
additional information
?
-
-
high concentrations of available violaxanthin, as found in enzyme assays with pure violaxanthin, lead to saturation of the VDE and a strong competition with the intermediate reaction product Ax, thus decreasing the ratio of the second deepoxidation rate to the first de-epoxidation rate
-
-
?
additional information
?
-
-
Mantoniella squamata VDE exhibits a very low ratio of the second de-epoxidation rate to the first de-epoxidation rate in thylakoids or in enzyme assays with thte purified light-harvesting complex. The interaction between the isolated light-harvesting complex and the VDE can influence the ratio of the two de-epoxidation rates. Mantoniella squamata VDE is able to de-epoxidize violaxanthin bound to spinach light harvesting complex II better than bound to Mantoniella squamata light harvesting complex II, the latter shows accumulation of intermediate antheraxanthin in the membranes, rate constants for first and second reaction step, overview
-
-
?
additional information
?
-
-
high concentrations of available violaxanthin, as found in enzyme assays with pure violaxanthin, lead to saturation of the VDE and a strong competition with the intermediate reaction product Ax, thus decreasing the ratio of the second deepoxidation rate to the first de-epoxidation rate
-
-
?
additional information
?
-
-
Mantoniella squamata VDE exhibits a very low ratio of the second de-epoxidation rate to the first de-epoxidation rate in thylakoids or in enzyme assays with thte purified light-harvesting complex. The interaction between the isolated light-harvesting complex and the VDE can influence the ratio of the two de-epoxidation rates. Mantoniella squamata VDE is able to de-epoxidize violaxanthin bound to spinach light harvesting complex II better than bound to Mantoniella squamata light harvesting complex II, the latter shows accumulation of intermediate antheraxanthin in the membranes, rate constants for first and second reaction step, overview
-
-
?
additional information
?
-
-
the level of violaxanthin de-epoxidase changes in an inverse, nonlinear relationship with respect to the VAZ pool (violaxanthin + antheraxanthin + zeaxanthin), suggesting that enzyme levels can be indirectly regulated by the VAZ pool
-
-
?
additional information
?
-
-
no activity with 9-cis neoxanthin and 9-cis violaxanthin
-
-
?
additional information
?
-
-
only the epoxy-oxygen at the 5,6(5',6') position of xanthophylls are cleaved by the VDE, whereas ring-spanning epoxides at position 3,6(3',6') are not accessible to the enzyme. The structure and chemical ligands of the second jonon ring are insignificant for the de-epoxidation of the 5,6-epoxy groups of the first ring. The epoxy-free second jonon ring is not involved in the binding of the xanthophyll to the catalytic center and does not affect the enzyme reaction. Due to steric hindrance, any tested cis-configuration in the polyene chain of the xanthophylls, as well as the 8-oxy group, in fucoxanthin, prevents the de-epoxidation
-
-
?
additional information
?
-
spinach VDE is able to de-epoxidize violaxanthin bound to spinach or Mantoniella squamata light harvesting complexes in a comparable manner, rate constants for first and second reaction step, overview
-
-
?
additional information
?
-
by measuring the initial formation of the product, enzyme VDE is found to convert a large number of violaxanthin molecules to antheraxanthin before producing any zeaxanthin, favoring a model where violaxanthin is bound non-symmetrically in VDE, overview
-
-
?
