| IED ID | IndEnz0019000001 |
| Enzyme Type ID | polyphenol oxidase000001 |
| Protein Name |
Polyphenol oxidase latent form, chloroplastic L-PaPPO PA-PPO Cleaved into: Polyphenol oxidase active form, chloroplastic A-PaPPO EC 1.10.3.1 |
| Gene Name | PPO |
| Organism | Prunus armeniaca (Apricot) (Armeniaca vulgaris) |
| Taxonomic Lineage | cellular organisms Eukaryota Viridiplantae Streptophyta Streptophytina Embryophyta Tracheophyta Euphyllophyta Spermatophyta Magnoliopsida Mesangiospermae eudicotyledons Gunneridae Pentapetalae rosids fabids Rosales Rosaceae Amygdaloideae Amygdaleae Prunus Prunus armeniaca (Apricot) (Armeniaca vulgaris) |
| Enzyme Sequence | MATAPSPTTMGTYSSLISTNSFSTFLPNKSQLSLSGKSKHYVARRSSISCKATNNNNSNNQNEQQEESSRLLGKLDRRNILIGLGGLYGATTLDRKPFAFADPIAPPDLTTCKPAEITPGGSETVPCCPPVTTKIKTFKPDLSIPLRTSPAAHQVTDEYLAKFKKAQAAMRALPDDDPRSMVQQAKVHCAYCNGAYPQVGFTDNDIQVHFSWLFFPFHRMYLYFYERILGKLIDDPTFALPYWNWDSPVGFPIPDIYTDTSSPLYDQYRNADHQPPVLVDLSYGGKDDDVDEQTRIDENLAIMYRQMVSGAKTPDLFFGHAYRAGNLNTGKYPGTIENMPHNNIHIWVGDPSQTHQEDMGNFYSAGRDPLFYAHHANVDRMWNIWKTLGGKRKDITDTDWLDAEFLFYDENAELVRVKVRDSLEPEKQLRYNYEPVSLPWLFTKPTARKTKNKTKAKVAATQLTSKFPATLVEVTTVEVARPKPRKRSKKEKVDEEELLIIKDIEFEGTEAVKFDVFINDDAESLSRRDKSEFAGSFVHVPQGKTTKAKTKTNLKLGITDLLEDLGAEDDSSVLVTLVPRVSNSPITIGGFKIEYSS |
| Enzyme Length | 597 |
| Uniprot Accession Number | O81103 |
| Absorption | |
| Active Site | |
| Activity Regulation | ACTIVITY REGULATION: Activated in the presence of substrate at low pH (PubMed:28812349). Specific activity fluctuates during fruit ripening, starting at immature-green stage, reaching a peak at the breaker stage, followed by a sharp decrease until the half-ripe stage to remain stable during the following development stages (PubMed:10198084). Triggered by CuSO(4) and by low concentrations of SDS. Repressed by several inhibitors including 4-hexylresorcinol, ascorbic acid, benzoic acid, kojic acid, glutathione (reduced form), L-cysteine and sodium metabisulfite. Inhibited by various salt such as FeSO(4), KCl, NaCl, CaCl(2), MnCl(2), NiCl(2) and AlCl(3). Spontaneously activated during storage at 4 degrees Celsius (PubMed:28812349). {ECO:0000269|PubMed:10198084, ECO:0000269|PubMed:28812349}. |
| Binding Site | |
| Calcium Binding | |
| catalytic Activity | CATALYTIC ACTIVITY: Reaction=2 catechol + O2 = 2 1,2-benzoquinone + 2 H2O; Xref=Rhea:RHEA:21632, ChEBI:CHEBI:15377, ChEBI:CHEBI:15379, ChEBI:CHEBI:17253, ChEBI:CHEBI:18135; EC=1.10.3.1; Evidence={ECO:0000269|PubMed:10198084, ECO:0000269|PubMed:28812349}; |
| DNA Binding | |
| EC Number | 1.10.3.1 |
| Enzyme Function | FUNCTION: [Polyphenol oxidase active form, chloroplastic]: Catalyzes the oxidation of mono- and o-diphenols to o-diquinones. Uses preferentially 4-methylcatechol and chlorogenic acid as substrates, followed by caffeic acid, pyrogallol, and catechol, but barely active toward dopamine and L-dopa. No activity detected with monophenols (e.g. phenol and tyramine). {ECO:0000269|PubMed:28812349}. |
| Temperature Dependency | BIOPHYSICOCHEMICAL PROPERTIES: Temperature dependence: Optimum temperature is 45 degrees Celsius with catechol as substrate. Completely inactivated after heating at 70 degrees Celsius for 10 min. {ECO:0000269|PubMed:28812349}; |
| PH Dependency | BIOPHYSICOCHEMICAL PROPERTIES: pH dependence: Optimum pH is 4.5 with catechol as substrate. {ECO:0000269|PubMed:28812349}; |
| Pathway | |
| nucleotide Binding | |
| Features | Chain (2); Compositional bias (1); Cross-link (1); Disulfide bond (2); Metal binding (6); Region (1); Site (1); Transit peptide (2) |
| Keywords | Chloroplast;Copper;Direct protein sequencing;Disulfide bond;Metal-binding;Oxidoreductase;Plastid;Thioether bond;Thylakoid;Transit peptide |
| Interact With | |
| Induction | |
| Subcellular Location | SUBCELLULAR LOCATION: Plastid, chloroplast thylakoid lumen {ECO:0000250|UniProtKB:Q6UIL3}. |
| Modified Residue | |
| Post Translational Modification | |
| Signal Peptide | |
| Structure 3D | |
| Cross Reference PDB | - |
| Mapped Pubmed ID | - |
| Motif | |
| Gene Encoded By | |
| Mass | 67,133 |
| Kinetics | BIOPHYSICOCHEMICAL PROPERTIES: Kinetic parameters: KM=2 mM for 4-methylcatechol {ECO:0000269|PubMed:28812349}; KM=2.7 mM for chlorogenic acid {ECO:0000269|PubMed:28812349}; KM=5.3 mM for catechol {ECO:0000269|PubMed:28812349}; KM=11 mM for pyrogallol {ECO:0000269|PubMed:28812349}; Note=kcat is 700 sec(-1) with 4-methylcatechol as substrate. kcat is 1400 sec(-1) with chlorogenic acid as substrate. kcat is 210 sec(-1) with catechol as substrate. kcat is 590 sec(-1) with pyrogallol as substrate. {ECO:0000269|PubMed:28812349}; |
| Metal Binding | METAL 188; /note=Copper A; /evidence=ECO:0000250|UniProtKB:Q9ZP19; METAL 209; /note=Copper A; /evidence=ECO:0000250|UniProtKB:Q9ZP19; METAL 218; /note=Copper A; /evidence=ECO:0000250|UniProtKB:Q9ZP19; METAL 341; /note=Copper B; /evidence=ECO:0000250|UniProtKB:Q9ZP19; METAL 345; /note=Copper B; /evidence=ECO:0000250|UniProtKB:Q9ZP19; METAL 375; /note=Copper B; /evidence=ECO:0000250|UniProtKB:Q9ZP19 |
| Rhea ID | RHEA:21632 |
| Cross Reference Brenda |