Any feedback?
Information on EC 1.11.1.11 - L-ascorbate peroxidase and Organism(s) Nicotiana tabacum and UniProt Accession Q42941
for references in articles please use BRENDA:EC1.11.1.11Please wait a moment until all data is loaded. This message will disappear when all data is loaded.
EC Tree
1.11.1.11 L-ascorbate peroxidaseIUBMB Comments
A heme protein. Oxidizes ascorbate and low molecular weight aromatic substrates. The monodehydroascorbate radical produced is either directly reduced back to ascorbate by EC 1.6.5.4 [monodehydroascorbate reductase (NADH)] or undergoes non-enzymic disproportionation to ascorbate and dehydroascorbate.
Specify your search results
Word Map
- 1.11.1.11
- catalase
- dismutase
- sod
- malondialdehyde
- seedling
-
chlorophyl
- dehydroascorbate
- guaiacol
- shoot
- drought
- biomass
- phenol
- chloroplast
- cultivar
- monodehydroascorbate
-
electrolyte
-
carotenoid
-
non-enzymatic
- cadmium
- peroxidases
- asa
- lipoxygenase
- thylakoidal
-
foliar
-
abscisic
- photosystem
-
stomatal
-
hydroponic
-
postharvest
- mdhar
- aestivum
- triticum
-
ascorbate-glutathione
-
photochemical
-
phytotoxicity
-
1.6.4.2
-
chilling
- phytochelatins
-
irrigation
-
non-photochemical
-
cd-induced
-
phytoextraction
-
transpiration
-
salt-stressed
-
hoagland
-
photoinhibition
- fe-sod
- juncea
- synthesis
- analysis
- agriculture
-
phytoremediation
-
ros-scavenging
The taxonomic range for the selected organisms is: Nicotiana tabacum
The enzyme appears in selected viruses and cellular organisms
The enzyme appears in selected viruses and cellular organisms
Synonyms
ascorbate peroxidase, apex2, cytosolic ascorbate peroxidase, lmapx, ascorbate peroxidase 2, l-ascorbate peroxidase, ascorbate peroxidase 1, ascorbic acid peroxidase, osapx8, osapx2, 
more
topSYNONYM 
ORGANISM
UNIPROT
COMMENTARY 
LITERATURE
ascorbate peroxidase
-
-
-
-
ascorbic acid peroxidase
-
-
-
-
L-ascorbic acid peroxidase
-
-
-
-
L-ascorbic acid-specific peroxidase
-
-
-
-
peroxidase, ascorbate
-
-
-
-
REACTION
REACTION DIAGRAM
COMMENTARY
ORGANISM
UNIPROT
LITERATURE
2 L-ascorbate + H2O2 + 2 H+ = 2 monodehydroascorbate + 2 H2O
mechanism, structural hints to instability during catalysis
-
REACTION TYPE
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
redox reaction
-
-
-
-
oxidation
-
-
-
-
reduction
-
-
-
-
peroxidation
-
-
-
-
PATHWAY SOURCE
PATHWAYS
BRENDA
-
-, -
SYSTEMATIC NAME
IUBMB Comments
L-ascorbate:hydrogen-peroxide oxidoreductase
A heme protein. Oxidizes ascorbate and low molecular weight aromatic substrates. The monodehydroascorbate radical produced is either directly reduced back to ascorbate by EC 1.6.5.4 [monodehydroascorbate reductase (NADH)] or undergoes non-enzymic disproportionation to ascorbate and dehydroascorbate.
CAS REGISTRY NUMBER
COMMENTARY
72906-87-7
-
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
INHIBITOR
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
IMAGE
2,2,6,6-tetramethylpiperidinyl-1-oxide
formation of 2,2,6,6-tetramethylpiperidinyl-1-oxy-adducts and subsequent oxidation of the cysteine residue located near the propionate group of heme leads to loss of enzyme activity
2,6-dichloroisonicotinic acid
-
54% inhibition at 0.1 mM, 95% inhibition at 1 mM, the inhibition is not time-dependent
H2O2
when inactivated by H2O2, heme is irreversibly cross-linked to the APX apoprotein. tsAPXW35F is inactivated in 3 min by H2O2. It is possible that tsAPXW35F is inactivated by adistinct mechanism because the heme can no longer be cross-linked to the enzyme
H2O2
wild-type enzyme has a half-time of inactivation of less than 10 sec. Triple mutant C26S/W35F/C126A retains 50% of the initial activity after H2O2 treatment for 3 min
salicylic acid
-
biologically active, reversible inhibition, 59% inhibition at 0.1 mM, 83% inhibition at 0.2 mM, 95% inhibition at 1 mM, the inhibition is not time-dependent
KM VALUE [mM]
SUBSTRATE
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
IMAGE
additional information
additional information
-
untreated cells, sigmoidal dependence of reaction rate on ascorbate concentration, in heat shock cells, hyperbolic dependence of reaction rate on ascorbate concentration and 5-fold decrease in Km-value
-
TURNOVER NUMBER [1/s]
SUBSTRATE
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
IMAGE
pH OPTIMUM
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
ORGANISM
COMMENTARY
LITERATURE
UNIPROT
SEQUENCE DB
SOURCE
SOURCE TISSUE
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
SOURCE
LOCALIZATION
ORGANISM
UNIPROT
COMMENTARY
GeneOntology No.
LITERATURE
SOURCE
GENERAL INFORMATION
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
metabolism
cytosolic ascorbate peroxidase is S-nitrosylated at the onset of programmed cell death, induced by both heat shock or hydrogen peroxide. S-nitrosylation of Apx is responsible for the rapid decrease in its activity, and the decrease in activity is a precocious event in the programmed cell death signaling pathway, occurring when no cellular death hallmarks are evident
UNIPROT
ENTRY NAME
ORGANISM
NO. OF AA
NO. OF TRANSM. HELICES
MOLECULAR WEIGHT[Da]
SOURCE
SEQUENCE
LOCALIZATION PREDICTION
The reliability class of the localization prediction ranges from 1 (very reliable) to 5 (not reliable).
The reliability class of the localization prediction ranges from 1 (very reliable) to 5 (not reliable). Q42941_TOBAC
250
0
27388
TrEMBL
other Location (Reliability: 3)
POSTTRANSLATIONAL MODIFICATION
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
additional information
additional information
cytosolic ascorbate peroxidase is S-nitrosylated at the onset of programmed cell death, induced by both heat shock or hydrogen peroxide
additional information
-
cytosolic ascorbate peroxidase is S-nitrosylated at the onset of programmed cell death, induced by both heat shock or hydrogen peroxide
CRYSTALLIZATION (Commentary)
ORGANISM
UNIPROT
LITERATURE
PROTEIN VARIANTS
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
C126A
kcat/KM for L-ascorbate is 1.4fold higher than wild-type enzyme. kcat/Km for H2O2 is 1.7fold lower than wild-type enzyme
C26S
C26S/C126A
kcat/KM for L-ascorbate is 1.3fold lower than wild-type enzyme. kcat/Km for H2O2 is 2.5fold lower than wild-type enzyme
C26S/W35F/C126A
kcat/KM for L-ascorbate is 1.6fold than wild-type enzyme. kcat/Km for H2O2 is 3.4fold lower than wild-type enzyme. Mutant shows increased tolerance to H2O2 (retains 50% of the initial activity after H2O2 treatment for 3 min) compared to wild-type enzyme (half-time of inactivation is less than 10 sec)
W35F
C26S
kcat/KM for L-ascorbate is 1.8fold lower than wild-type enzyme. kcat/Km for H2O2 is 3.1fold lower than wild-type enzyme
C26S
kcat/Km for L-ascorbate is 1.8fold lower than wild-type value. kcat/KM for H2O2 is 3.1fold lower than wild-type value. In contrast to wild-type enzyme, the mutant enzyme retains 60% of the initial activity after incubation for 10 min with the radical scavenger 2,2,6,6-tetramethylpiperidinyl-1-oxy and H2O2
W35F
kcat/KM for L-ascorbate is 2.6fold higher than wild-type enzyme. kcat/Km for H2O2 is 2.3fold lower than wild-type enzyme
W35F
mutation does not cause a significant change in the structure of tsAPX. Mutation increases H2O2 tolerance. 2.3fold decrease in KM-value for L-ascorbate. 4.3fold increase in Km-value for H2O2
REF.
AUTHORS
TITLE
JOURNAL
VOL.
PAGES
YEAR
ORGANISM (UNIPROT)
PUBMED ID
SOURCE
Durner, J.; Klessig, D.F.
Inhibition of ascorbate peroxidase by salicylic acid and 2,6-dichloroisonicotinic acid, two inducers of plant defense responses
Proc. Natl. Acad. Sci. USA
92
11312-11316
1995
Nicotiana tabacum
Kvaratskhelia, M.; George, S.J.; Thorneley, R.N.
Salicylic acid is a reducing substrate and not an effective inhibitor of ascorbate peroxidase
J. Biol. Chem.
272
20998-21001
1997
Camellia sinensis, Nicotiana tabacum
Wada, K.; Tada, T.; Nakamura, Y.; Ishikawa, T.; Yabuta, Y.; Yoshimura, K.; Shigeoka, S.; Nishimura, K.
Crystal structure of chloroplastic ascorbate peroxidase from tobacco plants and structural insights into its instability
J. Biochem.
134
239-244
2003
Nicotiana tabacum
Vacca, R.A.; de Pinto, M.C.; Valenti, D.; Passarella, S.; Marra, E.; De Gara, L.
Production of reactive oxygen species, alteration of cytosolic ascorbate peroxidase, and impairment of mitochondrial metabolism are early events in heat shock-induced programmed cell death in tobacco Bright-Yellow 2 cells
Plant Physiol.
134
1100-1112
2004
Nicotiana tabacum
Kitajima, S.; Kitamura, M.; Koja, N.
Triple mutation of Cys26, Trp35, and Cys126 in stromal ascorbate peroxidase confers H2O2 tolerance comparable to that of the cytosolic isoform
Biochem. Biophys. Res. Commun.
372
918-923
2008
Nicotiana tabacum (Q9TNL9)
Kitajima, S.; Shimaoka, T.; Kurioka, M.; Yokota, A.
Irreversible cross-linking of heme to the distal tryptophan of stromal ascorbate peroxidase in response to rapid inactivation by H2O2
FEBS J.
274
3013-3020
2007
Nicotiana tabacum (Q9TNL9)
Kitajima, S.; Kurioka, M.; Yoshimoto, T.; Shindo, M.; Kanaori, K.; Tajima, K.; Oda, K.
A cysteine residue near the propionate side chain of heme is the radical site in ascorbate peroxidase
FEBS J.
275
470-480
2008
Galdieria partita, Nicotiana tabacum (Q9TNL9), Nicotiana tabacum
de Pinto, M.C.; Locato, V.; Sgobba, A.; Romero-Puertas, M.D.; Gadadeta, C.; Delledonne, M.; De Gara, L.
S-Nitrosylation of ascorbate peroxidase is part of programmed cell death signaling in tobacco Bright Yellow-2 cells
Plant Physiol.
163
1766-1775
2013
Nicotiana tabacum (Q42941), Nicotiana tabacum
EXTERNAL LINKS (specific for EC-Number 1.11.1.11)
Use of this online version of BRENDA is free under the CC BY 4.0 license. See terms of use for full details.
Release 2023.1 (January 2023)
Legal
Curated at
Member of
