:Cannabidiolic acid synthase
{{see also|Tetrahydrocannabinolic acid synthase}}
{{Infobox enzyme
| Name = Cannabidiolic acid synthase
| EC_number = 1.21.3.8
| CAS_number =
| GO_code =
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Cannabidiolic acid synthase ({{EC number|1.21.3.8}}, CBDA synthase) is an enzyme with systematic name cannabigerolate:oxygen oxidoreductase (cyclizing, cannabidiolate-forming).{{cite journal | vauthors = Taura F, Morimoto S, Shoyama Y | title = Purification and characterization of cannabidiolic-acid synthase from Cannabis sativa L.. Biochemical analysis of a novel enzyme that catalyzes the oxidocyclization of cannabigerolic acid to cannabidiolic acid | journal = The Journal of Biological Chemistry | volume = 271 | issue = 29 | pages = 17411–6 | date = July 1996 | pmid = 8663284 | doi = 10.1074/jbc.271.29.17411 | doi-access = free }}{{cite journal | vauthors = Taura F, Sirikantaramas S, Shoyama Y, Yoshikai K, Shoyama Y, Morimoto S | title = Cannabidiolic-acid synthase, the chemotype-determining enzyme in the fiber-type Cannabis sativa | journal = FEBS Letters | volume = 581 | issue = 16 | pages = 2929–34 | date = June 2007 | pmid = 17544411 | doi = 10.1016/j.febslet.2007.05.043 | doi-access = free }} It is an oxidoreductase found in Cannabis sativa that catalyses the formation of cannabidiolate, a carboxylated precursor of cannabidiol.
Enzyme structure
Cannabidiolic acid synthase consists of a single protein with a molecular mass of 74 kDa. Its amino acid sequence is partly (40-50%) homologous to several other oxidoreductases, such as berberine bridge enzyme in Eschscholzia californica{{cite journal | vauthors = Kutchan TM, Dittrich H | title = Characterization and mechanism of the berberine bridge enzyme, a covalently flavinylated oxidase of benzophenanthridine alkaloid biosynthesis in plants | journal = The Journal of Biological Chemistry | volume = 270 | issue = 41 | pages = 24475–81 | date = October 1995 | pmid = 7592663 | doi = 10.1074/jbc.270.41.24475 | doi-access = free }} and Nectarin V in Nicotiana langsdorffii X N. sanderae.{{cite journal | vauthors = Carter CJ, Thornburg RW | title = Tobacco nectarin V is a flavin-containing berberine bridge enzyme-like protein with glucose oxidase activity | journal = Plant Physiology | volume = 134 | issue = 1 | pages = 460–9 | date = January 2004 | pmid = 14730073 | pmc = 316325 | doi = 10.1104/pp.103.027482 }}
CBDA synthase has four binding sites; two for FAD and two for the substrate.{{cite web |url=https://www.uniprot.org/uniprot/A6P6V9 |title=CBDAS - Cannabidiolic acid synthase precursor - Cannabis sativa (Hemp) - CBDAS gene & protein |website=UniProt |access-date=26 February 2016}}
Enzyme function
Cannabidiolic acid synthase catalyses the production of cannabidiolate predominantly from cannabigerolate by stereospecific oxidative cyclization of the geranyl group of cannabigerolic acid according to the following chemical reaction:
: cannabigerolate + O2 → cannabidiolate + H2O2
Cannabinerolate can also be used as a substrate, but with lower efficiency (KM=0.137 mM) than cannabigerolate (KM=0.206 mM). It covalently binds FAD, and does require coenzymes & molecular oxygen for the oxidocyclization reaction.
References
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External links
- {{MeshName|Cannabidiolic+acid+synthase}}
{{Other oxidoreductases}}
{{Enzymes}}
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