Cloned (Comment) | Organism |
---|---|
gene BCO2, sequence comparisons, recombinant expression of His-tagged enzyme in Escherichia coli strain BL21-Gold (DE3) | Gallus gallus |
gene BCO2, sequence comparisons, recombinant expression of His-tagged, catalytically inactive enzyme BCO2 in Escherichia coli strain BL21-Gold (DE3), mostly in inclusion bodies | Homo sapiens |
Localization | Comment | Organism | GeneOntology No. | Textmining |
---|---|---|---|---|
mitochondrion | - |
Gallus gallus | 5739 | - |
Natural Substrates | Organism | Comment (Nat. Sub.) | Natural Products | Comment (Nat. Pro.) | Rev. | Reac. |
---|---|---|---|---|---|---|
all-trans-beta-carotene + O2 | Gallus gallus | - |
all-trans-10'-apo-beta-carotenal + beta-ionone | - |
? | |
all-trans-beta-carotene + O2 | Homo sapiens | - |
all-trans-10'-apo-beta-carotenal + beta-ionone | - |
? |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Gallus gallus | E1C8E0 | - |
- |
Homo sapiens | B2RCV8 | - |
- |
Purification (Comment) | Organism |
---|---|
a small amount of recombinant, catalytically inactive His-tagged enzyme from Escherichia coli strain BL21-Gold (DE3) by cobalt affinity chromatography | Homo sapiens |
recombinant His-tagged enzyme from Escherichia coli strain BL21-Gold (DE3) by cobalt affinity chromatography | Gallus gallus |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
9-cis-beta-carotene + O2 | - |
Gallus gallus | 9-cis-beta-apo-10'-carotenal + beta-ionone | - |
? | |
all-trans-beta-carotene + O2 | - |
Gallus gallus | all-trans-10'-apo-beta-carotenal + beta-ionone | - |
? | |
all-trans-beta-carotene + O2 | - |
Homo sapiens | all-trans-10'-apo-beta-carotenal + beta-ionone | - |
? | |
alpha-carotene + O2 | - |
Gallus gallus | beta-apo-10'-carotenal + alpha-apo-10'-carotenal | - |
? | |
beta-cryptoxanthin + O2 | - |
Gallus gallus | 3-hydroxy-beta-apo-10'-carotenal + beta-ionone | - |
? | |
beta-cryptoxanthin + O2 | - |
Gallus gallus | 3-hydroxy-beta-apo-8'-carotenal + beta-cyclocitral | - |
? | |
beta-cryptoxanthin + O2 | - |
Gallus gallus | beta-apo-10'-carotenal + 3-hydroxy-beta-ionone | - |
? | |
lutein + O2 | - |
Gallus gallus | 3-hydroxy-alpha-apo-10'-carotenal + 3-hydroxy-beta-ionone | - |
? | |
lutein + O2 | - |
Gallus gallus | 3-hydroxy-beta-apo-10'-carotenal + 3-hydroxy-alpha-ionone | - |
? | |
additional information | like BCO1, EC 1.13.11.63, purified recombinant chicken BCO2 catalyzes the oxidative cleavage of the provitamin A carotenoids beta-carotene, alpha-carotene, and beta-cryptoxanthin. Its catalytic activity with beta-carotene as substrate is at least 10fold lower than that of BCO1. Purified recombinant chicken BCO2 also catalyzes the oxidative cleavage of 9-cis-beta-carotene and the non-provitamin A carotenoids zeaxanthin and lutein, and is inactive with all-trans-lycopene and beta-apo-carotenoids. Apo-10'-carotenoids are detected as enzymatic products by HPLC, and the identities are confirmed by LC-MS. Small amounts of 3-hydroxy-beta-apo-8'-carotenal are also consistently detected in BCO2-beta-cryptoxanthin reaction mixtures. With the exception of this activity with beta-cryptoxanthin, BCO2 cleaves specifically at the 9'-10'-bond to produce apo-10'-carotenoids. BCO2 is regioselective (or even regiospecific) for the trans 9'-10'-end of 9-cis-beta-carotene due to the size of the substrate tunnel. Unlike murine BCO2, chicken BCO2 cannot perform a second cleavage on beta-apo-10'-carotenal to yield rosafluene dialdehyde, and it has no activity with all-trans-lycopene, while it cleaves cis-lycopene isomers. Chicken BCO2 also does not have activity with the other beta-apocarotenals in the series (beta-apo-8'-carotenal, beta-apo-12'-carotenal, and beta-apo-14'-carotenal). Importance of the 3-hydroxy-beta-ionone ring for BCO2 cleavage, preference of BCO2 for substrates that contain a 3-hydroxy-beta-ionone ring | Gallus gallus | ? | - |
? | |
zeaxanthin + O2 | - |
Gallus gallus | 3-hydroxy-beta-apo-10'-carotenal + 3-hydroxy-beta-ionone | - |
? |
Synonyms | Comment | Organism |
---|---|---|
BCO2 | - |
Gallus gallus |
BCO2 | - |
Homo sapiens |
beta-carotene 9',10'-oxygenase | - |
Gallus gallus |
beta-carotene 9',10'-oxygenase | - |
Homo sapiens |
Temperature Optimum [°C] | Temperature Optimum Maximum [°C] | Comment | Organism |
---|---|---|---|
37 | - |
assay at | Gallus gallus |
37 | - |
assay at | Homo sapiens |
pH Optimum Minimum | pH Optimum Maximum | Comment | Organism |
---|---|---|---|
8 | - |
assay at | Gallus gallus |
8 | - |
assay at | Homo sapiens |
General Information | Comment | Organism |
---|---|---|
metabolism | the substrates that are inactive with BCO2 (all-trans-lycopene and beta-apocarotenals) are substrates for BCO1 | Gallus gallus |
physiological function | beta-carotene 9',10'-oxygenase (BCO2) catalyzes the oxidative cleavage of carotenoids at the 9'-10'-bond to yield an ionone and an apo-10'-carotenoid | Homo sapiens |
physiological function | beta-carotene 9',10'-oxygenase (BCO2) catalyzes the oxidative cleavage of carotenoids at the 9'-10'-bond to yield an ionone and an apo-10'-carotenoid. Chicken BCO2 has broader substrate specificity than BCO1, consistent with its proposed function of preventing oxidative stress brought about by carotenoid accumulation in the mitochondria. It cleaves only full-length carotenoids with ionone rings, and the hydroxylated carotenoids are cleaved to a greater extent than their hydrocarbon counterparts under the conditions tested | Gallus gallus |