Cloned (Comment) | Organism |
---|---|
gene MaAPX1, phenotype and genotyping, DNA and amino acid sequence determination and analysis, sequence comparisons and phylogenetic analysis, quantitative RT-PCR expression analysis of MaMsrB2 and MaAPX1 genes. Recombinant expression of His-tagged wild-type and mutant enzymes in Escherichia coli strain BL21(DE3), coexpression of gene MsrB2 as His-tagged enzyme. Ectopic recombinant overexpression of MaAPX1 in Arabidopsis thaliana leading to delay of the detached leaf senescence induced by dark in Arabidopsis | Musa acuminata |
Protein Variants | Comment | Organism |
---|---|---|
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 | Musa acuminata |
Metals/Ions | Comment | Organism | Structure |
---|---|---|---|
Fe2+ | in the heme group | Musa acuminata |
Natural Substrates | Organism | Comment (Nat. Sub.) | Natural Products | Comment (Nat. Pro.) | Rev. | Reac. |
---|---|---|---|---|---|---|
2 L-ascorbate + H2O2 + 2 H+ | Musa acuminata | - |
L-ascorbate + L-dehydroascorbate + 2 H2O | - |
? |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Musa acuminata | A0A089H0K2 | Musa AB Group | - |
Posttranslational Modification | Comment | Organism |
---|---|---|
additional information | sulfoxidation of MaAPX1, i.e. methionine oxidation, leads to loss of the activity, which is repaired partially by Musa acuminate methionine sulfoxide reductase B2 (MsrB2). The redox state of methionine in MaAPX1 is critical to its activity, and MaMsrB2 can regulate the redox state and activity of MaAPX1. Analysis of the post-translational redox modification of APX | Musa acuminata |
Purification (Comment) | Organism |
---|---|
recombinant His-tagged wild-type and mutant enzymes from Escherichia coli strain BL21(DE3) by glutathione and nickel affinity chromatography | Musa acuminata |
Source Tissue | Comment | Organism | Textmining |
---|---|---|---|
fruit | green mature banana fruit approximately 110 days after anthesis, harvested from an orchard in Guangzhou, Guangdong province, China. MaMsrB2 and MaAPX1 are isolated from a banana transcriptome database. Their transcript levels in the peel during fruit ripening and senescence are investigated by quantitative real-time PCR expression analysis | Musa acuminata | - |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
2 L-ascorbate + H2O2 + 2 H+ | - |
Musa acuminata | L-ascorbate + L-dehydroascorbate + 2 H2O | - |
? | |
additional information | interaction analysis of enzyme MaAPX1 with enzyme MaMsrB2, overview. The repair of oxidized MaAPX1 is conducted by incubating oxidized proteins (0.002 mM each) and 10 mM DTT at 37°C for 3 h | Musa acuminata | ? | - |
- |
Synonyms | Comment | Organism |
---|---|---|
APX | - |
Musa acuminata |
ascorbate peroxidase | - |
Musa acuminata |
MaAPX1 | - |
Musa acuminata |
Temperature Optimum [°C] | Temperature Optimum Maximum [°C] | Comment | Organism |
---|---|---|---|
22 | - |
assay at | Musa acuminata |
pH Optimum Minimum | pH Optimum Maximum | Comment | Organism |
---|---|---|---|
7 | - |
assay at | Musa acuminata |
Cofactor | Comment | Organism | Structure |
---|---|---|---|
heme | - |
Musa acuminata |
General Information | Comment | Organism |
---|---|---|
evolution | gene MaAPX1 has a high homology (83.9%) with Arabidopsis thaliana gene APX1 | Musa acuminata |
malfunction | ectopic recombinant overexpression of MaAPX1 delays the detached leaf senescence induced by darkness in Arabidopsis thaliana | Musa acuminata |
metabolism | methionine sulfoxide reductase B regulates the activity of ascorbate peroxidase of banana fruit, proposed model of the involvement of MaMsrB2-mediated redox modification of methionine in MaAPX1 in regulating ripening and senescence, overview | Musa acuminata |
physiological function | MaAPX1 interacts with methionine sulfoxide reductase B2 (MsrB2) in bananas. Enzyme MaAPX1 might be a target of MaMsrB2 by Co-IP and mass spectrum techniques in banana fruit. The redox state of methionine in MaAPX1 is critical to its activity, and MaMsrB2 can regulate the redox state and activity of MaAPX1. Among the antioxidant enzymes, APX plays a crucial role in scavenging H2O2 by catalyzing the conversion of H2O2 to H2O and O2, using ascorbic acid as the electron donor. APX has a higher affinity than does catalase for H2O2 and contributes maximally to H2O2 detoxification in chloroplasts, cytosol, mitochondria, and peroxisomes, as well as in the apoplastic space. APX is involved in the physiological and developmental response, such as seed germination, leaf senescence, and programmed cell death. APX also participates in environmental stresses in plants, including drought, salt, chilling, photo-oxidative stress, and high temperature. MaAPX 1 might be involved in ripening and senescence in relation to oxidative stress | Musa acuminata |