1.11.1.11: L-ascorbate peroxidase
This is an abbreviated version!
For detailed information about L-ascorbate peroxidase, go to the full flat file.
Word Map on EC 1.11.1.11
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1.11.1.11
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catalase
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dismutase
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sod
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malondialdehyde
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seedling
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chlorophyl
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dehydroascorbate
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guaiacol
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shoot
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drought
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biomass
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phenol
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chloroplast
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cultivar
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monodehydroascorbate
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electrolyte
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carotenoid
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non-enzymatic
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cadmium
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peroxidases
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asa
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lipoxygenase
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thylakoidal
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foliar
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abscisic
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photosystem
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stomatal
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hydroponic
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postharvest
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mdhar
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aestivum
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triticum
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ascorbate-glutathione
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photochemical
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phytotoxicity
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1.6.4.2
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chilling
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phytochelatins
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irrigation
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non-photochemical
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cd-induced
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phytoextraction
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transpiration
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salt-stressed
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hoagland
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photoinhibition
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fe-sod
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juncea
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synthesis
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analysis
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agriculture
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phytoremediation
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ros-scavenging
- 1.11.1.11
- catalase
- dismutase
- sod
- malondialdehyde
- seedling
-
chlorophyl
- dehydroascorbate
- guaiacol
- shoot
- drought
- biomass
- phenol
- chloroplast
- cultivar
- monodehydroascorbate
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electrolyte
-
carotenoid
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non-enzymatic
- cadmium
- peroxidases
- asa
- lipoxygenase
- thylakoidal
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foliar
-
abscisic
- photosystem
-
stomatal
-
hydroponic
-
postharvest
- mdhar
- aestivum
- triticum
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ascorbate-glutathione
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photochemical
-
phytotoxicity
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1.6.4.2
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chilling
- phytochelatins
-
irrigation
-
non-photochemical
-
cd-induced
-
phytoextraction
-
transpiration
-
salt-stressed
-
hoagland
-
photoinhibition
- fe-sod
- juncea
- synthesis
- analysis
- agriculture
-
phytoremediation
-
ros-scavenging
Reaction
2 L-ascorbate
+
Synonyms
Am-pAPX1, APEX2, APOX, APX, APX 1, APX 2, APX1, APX2, APX3, APX4, APX5, APX6, APX7, APx8, APXS, APXT, ascorbate peroxidase, ascorbate peroxidase 1, ascorbate peroxidase 2, ascorbate peroxidase 3, ascorbate peroxidase 4, ascorbate peroxidase 5, ascorbate peroxidase 6, ascorbate peroxidase 7, ascorbate peroxidase 8, ascorbate peroxidase6, ascorbic acid peroxidase, At1g07890, AT1G77490, AT3G09640, AT4G08390, AT4G32320, AT4G35000, AT4G35970, AtAPx08, AtAPX1, AtAPX2, AtAPX3, AtAPX5, AtAPX6, AtSAPX, AtstAPX, AtTAPX, cAPX, cAPX 2, CmstAPX, CrAPX4, CreAPX1, CreAPX2, CreAPX4, CreAPXheme, CsAPX1, cytoplasmic ascorbate peroxidase 1, cytosolic ascorbate peroxidase, GhAPX1, glyoxysomal APX, HvAPX1, L-ascorbate peroxidase, L-ascorbate peroxidase 3, L-ascorbate peroxidase 5, L-ascorbate peroxidase 6, L-ascorbate peroxidase, heme-containing, L-ascorbic acid peroxidase, L-ascorbic acid-specific peroxidase, LmAPX, MaAPX1, OsAPx1, OsAPx2, OsAPx3, OsAPx4, OsAPx5, OsAPx6, OsAPx7, OsAPx8, OsAPXa, OsAPXb, pAPX, Pavirv00022559m, peroxidase, ascorbate, peroxisomal ascorbate peroxidase, PgAPX1, PHYPA_001206, PHYPA_001884, PHYPA_021776, PHYPA_024580, PHYPA_024582, Potri.002G081900, Potri.004G174500, Potri.005G112200, Potri.005G161900, Potri.005G179200, Potri.006G089000, Potri.006G132200, Potri.006G254500, Potri.009G015400, Potri.009G134100, Potri.016G084800, PpAPX, PpAPX-S, PpAPX2, PpAPX2.1, PpAPX2.2, PpAPX3, PpAPX6-related, PtAPX-S.1, PtAPX-S.2, PtAPX-TL29, PtAPX.3, PtAPX1.1, PtAPX1.2, PtAPX2, PtAPX3, PtAPX5, PtAPX5-like, PtAPX6 related, PtotAPX, RcAPX, sAPX, stromal APX, stromal ascorbate peroxidase, stromal ascorbate peroxidases, TaAPX, tAPX, thylakoid ascorbate peroxidase, thylakoid membrane-bound ascorbate peroxidases, thylakoid-bound ascorbate peroxidase
ECTree
1.11.1.11 L-ascorbate peroxidaseAdvanced search results
results (
results (Engineering
Engineering on EC 1.11.1.11 - L-ascorbate peroxidase
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PROTEIN VARIANTS 
ORGANISM
UNIPROT
COMMENTARY 
LITERATURE
C25S
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kcat/Km for L-ascorbate is 5.4fold lower than wild-type value. kcat/KM for H2O2 is 2.1fold lower than wild-type value. In contrast to wild-type enzyme, the mutant enzyme retains more than 90% of the initial activity after incubation for 10 min with the radical scavenger 2,2,6,6-tetramethylpiperidinyl-1-oxy and H2O2
C25S/C121S
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kcat/Km for L-ascorbate is 4.5fold lower than wild-type value. kcat/KM for H2O2 is 2.1fold lower than wild-type value. In contrast to wild-type enzyme, the mutant enzyme retains more than 90% of the initial activity after incubation for 10 min with the radical scavenger 2,2,6,6-tetramethylpiperidinyl-1-oxy and H2O2
K14D/W41F/E112K/A134P
W41A
the mutant is a six-coordinate heme peroxidase which has bis-histidine coordination, like a cytochrome, but that is catalytically active because the distal histidine reversibly dissociates to form a five-coordinate heme in response to binding of hydrogen peroxide
W208F
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the optical spectrum of the W208F mutant closely resembles that of wild type LmAPX at pH 7.5 in the absence of ascorbate. W208F mutant causes a spectral red shift from high spin to low spin, indicating that the mutant can react with H2O2. Cytochrome c binding affinity to the enzyme does not alter after mutation. The mutant is 1000times less active than the wild type in cytochrome c oxidation
M36Q
site-directed mutagenesis, mimicking sulfoxidation by mutating Met36 to Gln also decreases its activity in vitro and in vivo, whereas substitution of Met36 with Val36 to mimic the blocking of sulfoxidation has little effect on APX activity. Mimicking sulfoxidation of Met36 hinders the formation of compound I, the first intermediate between APX and H2O2
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
R172S
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negligible ascorbate peroxidase activity, but shows near wild type activity toward other aromatic substrates
A143P
site-directed mutagenesis of the delta-site of substrate oxidation, the electronic absorption spectra and dissociation constants for binding of cyanide and azide to the isolated heme are not significantly different for the mutant compared to wild-type, also the rate constants in the peroxidase reaction mechanism are not significantly affected by the replacement of A134 by proline. The insertion of a proline does not substantially alter the product distribution in APX
C32S
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the mutation leads to approximately 70% drop in ascorbate peroxidase activity with no effect on guaiacol peroxidase activity, these results indicate that uncharged aromatic substrates and the anionic ascorbate molecule interact with different sites on the enzyme
H42A
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inactive, partial recovery of activity by addition of exogenous imidazoles
S160M
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expression of apo-protein in Escherichia coli, reconstitution with exogenous heme, gives kinetic properties similar to wild-type enzyme
W41A
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the mutation enables the efficient conversion of recombinant enzyme into a stereoselective oxidizing agent for sulfides
D207A
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site-directed mutagenesis, the mutant retains 18.5% activity of the wild-type activity
H162L
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site-directed mutagenesis, the mutant retains 24.2% activity of the wild-type activity
H42L
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site-directed mutagenesis, the mutant retains 23.5% activity of the wild-type activity
CCP2APX
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residues 30-42, LREDDEYDNYIGY, of wild-type CCP are replaced with residues 27-32, IAEKKC, of APX in order to introduce the ascorbate-binding loop, a N184R point mutation is added
CCP2APX/F191
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in order to enable CCP2APX to form a porphyrin pi-cation radical during catalysis, Trp191 is converted to Phe
additional information
K14D/W41F/E112K/A134P
APEX2, i.e. engineered mutant of APX. APEX2 fused to a protein of interest covalently tags nearby proteins with biotin-phenol when H2O2 is added. High osmolarity and disruption of cell wall integrity permits live-cell biotin labeling in Schizosaccharomyces pombe and Saccharomyces cerevisiae, respectively. APEX2 permits targeted and proximity-dependent labeling of proteins
K14D/W41F/E112K/A134P
i.e. APEX2, engineered mutant of APX used for biotinylation of neighboring endogenous proteins. APEX labeling functions effectively in multiple Drosophila melanogaster tissues for different subcellular compartments and maps the mitochondrial matrix proteome of Drosophila muscle in different physiological conditions
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
additional information
expression with hyperacidic fusion partners such as C-end tail of human alpha-synuclein, C-end tails of Arabidopsis tubulins, TUA2 and TUB3, Escherichia coli msyB and C-end tail of Escherichia coli yjgD efficiently improves the thermostability and prevents thermal inactivation of APX1 with an elevated heat tolerance of at least 2°C
additional information
expression analysis of cytosolic APX isozymes in recombinant Nicotiana benthamiana shows that only APX6 displays a gradual increase in expression along the leaf blade with about a 4 and a 30fold higher level in the mid and tip sections, respectively, compared with the base. The changes in the level of APX6 correlate with the changes in the expression of the senescence marker gene SAG12. The age-dependent activation of the APX6 promoter is proven by APX6pro::GUS expression in leaves at different ages of the plants, phenotypes, detailed overview
additional information
generation of stromal and thylakoid membrane-bound ascorbate peroxidases (sAPX and tAPX, respectively) knockout mutants, exhibiting no visible phenotype under high-light (HL) stress. The Arabidopsis thaliana sapx/tapx double mutant is crossed with a proton gradient regulation 5 (pgr5) single mutant, wherein both DELTApH-dependent mechanisms are impaired. The sapx/tapx/pgr5 triple mutant exhibits extreme sensitivity to HL compared with its parental lines. This phenotype is consistent with cellular redox perturbations and enhanced expression of many oxidative stress-responsive genes. These findings demonstrate that the PGR5-dependent mechanisms compensate for chloroplast APXs, and vice versa. The failure of induction of non-photochemical quenching in pgr5 (because of the limitation in DELTApH formation) is partially recovered in sapx/tapx/pgr5 mutants. This recovery is dependent on the NADH dehydrogenase-like complex-dependent pathway for cyclic electron flow around photosystem I
additional information
generation of stromal and thylakoid membrane-bound ascorbate peroxidases (sAPX and tAPX, respectively) knockout mutants, exhibiting no visible phenotype under high-light (HL) stress. The Arabidopsis thaliana sapx/tapx double mutant is crossed with a proton gradient regulation 5 (pgr5) single mutant, wherein both DELTApH-dependent mechanisms are impaired. The sapx/tapx/pgr5 triple mutant exhibits extreme sensitivity to HL compared with its parental lines. This phenotype is consistent with cellular redox perturbations and enhanced expression of many oxidative stress-responsive genes. These findings demonstrate that the PGR5-dependent mechanisms compensate for chloroplast APXs, and vice versa. The failure of induction of non-photochemical quenching in pgr5 (because of the limitation in DELTApH formation) is partially recovered in sapx/tapx/pgr5 mutants. This recovery is dependent on the NADH dehydrogenase-like complex-dependent pathway for cyclic electron flow around photosystem I
additional information
overexpression CsAPX1 in Arabidopsis thaliana indicates that the decrease of AsA content and APX activity in transgenic lines is less significant than that of the wild-type during postharvest storage under light/dark conditions
additional information
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overexpression CsAPX1 in Arabidopsis thaliana indicates that the decrease of AsA content and APX activity in transgenic lines is less significant than that of the wild-type during postharvest storage under light/dark conditions
additional information
expression of Cyanidioschyzon merolae-derived APX (cAPX) in mammalian cells increases cellular antioxidative capacity. Heat and H2O2 stimulation results in ROS production. cAPX-expressing cells are more tolerant to oxidative stress induced by heat, H2O2, and acid stimulations than control cells lacking cAPX
additional information
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expression of Cyanidioschyzon merolae-derived APX (cAPX) in mammalian cells increases cellular antioxidative capacity. Heat and H2O2 stimulation results in ROS production. cAPX-expressing cells are more tolerant to oxidative stress induced by heat, H2O2, and acid stimulations than control cells lacking cAPX
additional information
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generation of transgenic cotton with changes of endogenous ROS by overexpressing or suppressing the expression of cytosolic ascorbate peroxidases (APXs). Downregulation of cytosolic ascorbate peroxidases inhibits the development of sink organs in Gossipium hirsutum. Plant growth and plant size, including plant heights and leaf sizes (lengths and widths), are seriously reduced in the cAPX-suppressed cottons compared to wild-type plants, phenotypes, detailed overview. Downregulated expression of cAPXs inhibits the development of cotton bolls, fibers, and seeds and reduces the storage capacity of the sink organs. The photosynthetic rate is suppressed in the mutant plants. Overexpression of GhAPX1 has little effect on the photosynthetic characteristics of the plants, except that the transpiration rate (Trmmol) and leaf surface temperature (CTleaf) are lower than in the control plant. The downregulation of cytosolic ascorbate peroxidases (APXs) decreases the water content and increases the water loss rate in cotton leaf
additional information
expression with hyperacidic fusion partners such as C-end tail of human alpha-synuclein, C-end tails of Arabidopsis tubulins, TUA2 and TUB3, Escherichia coli msyB and C-end tail of Escherichia coli yjgD efficiently improves the thermostability and prevents thermal inactivation of APX1 with an elevated heat tolerance of at least 2°C
additional information
-
expression with hyperacidic fusion partners such as C-end tail of human alpha-synuclein, C-end tails of Arabidopsis tubulins, TUA2 and TUB3, Escherichia coli msyB and C-end tail of Escherichia coli yjgD efficiently improves the thermostability and prevents thermal inactivation of APX1 with an elevated heat tolerance of at least 2°C
additional information
attempts to decrease heme accessibility through introduction of a Phe residue at position134 are unsuccessful because the A134F variant is isolated as the apoform from Escherichia coli and reconstitution protocols with exogenous heme do not generate catalytically active enzyme
additional information
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overexpression or suppression of PtoAPX in Populus tomentosa callus. Light-induced chloroplast development is enhanced in PtotAPX-overexpressing transgenic Populus tomentosa callus with lower levels of hydrogen peroxide, but is suppressed in PtotAPX antisense transgenic callus with higher levels of hydrogen peroxide. The suppression of light-induced chloroplast development in PtotAPX antisense transgenic callus is relieved by the exogenous reactive oxygen species scavenging agent N,N'-dimethylthiourea (DMTU)
additional information
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mutant lacking activity of isozyme TaAPX-6B, reduction of total enzymic activity by 40%, mutants show significantly reduced photosynthetic activity and biomass accumulation when grown at high-light intensity photosystem II electron transfer, but no oxidative damage
