Cannabidiolic acid synthase explained
See also: Tetrahydrocannabinolic acid synthase.
| Cannabidiolic acid synthase |
| Ec Number: | 1.21.3.8 |
Cannabidiolic acid synthase (CBDA synthase) is an enzyme with systematic name cannabigerolate:oxygen oxidoreductase (cyclizing, cannabidiolate-forming).[1] [2] It is an oxidoreductase found in Cannabis sativa that catalyses the formation of cannabidiolate, a carboxylated precursor of cannabidiol.[2]
Enzyme structure
Cannabidiolic acid synthase consists of a single protein with a molecular mass of 74 kDa.[1] Its amino acid sequence is partly (40-50%) homologous to several other oxidoreductases,[2] such as berberine bridge enzyme in Eschscholzia californica[3] and Nectarin V in Nicotiana langsdorffii X N. sanderae.[4]
CBDA synthase has four binding sites; two for FAD and two for the substrate.[5]
Enzyme function
Cannabidiolic acid synthase catalyses the production of cannabidiolate predominantly from cannabigerolate by stereospecific oxidative cyclization of the geranyl group of cannabigerolic acid[2] 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.[1]
The optimum pH for CBDA synthase is 5.0.[2]
Notes and References
- Taura F, Morimoto S, Shoyama Y . 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 . The Journal of Biological Chemistry . 271 . 29 . 17411–6 . July 1996 . 8663284 . 10.1074/jbc.271.29.17411 . free .
- Taura F, Sirikantaramas S, Shoyama Y, Yoshikai K, Shoyama Y, Morimoto S . Cannabidiolic-acid synthase, the chemotype-determining enzyme in the fiber-type Cannabis sativa . FEBS Letters . 581 . 16 . 2929–34 . June 2007 . 17544411 . 10.1016/j.febslet.2007.05.043 . free .
- Kutchan TM, Dittrich H . Characterization and mechanism of the berberine bridge enzyme, a covalently flavinylated oxidase of benzophenanthridine alkaloid biosynthesis in plants . The Journal of Biological Chemistry . 270 . 41 . 24475–81 . October 1995 . 7592663 . 10.1074/jbc.270.41.24475 . free .
- Carter CJ, Thornburg RW . Tobacco nectarin V is a flavin-containing berberine bridge enzyme-like protein with glucose oxidase activity . Plant Physiology . 134 . 1 . 460–9 . January 2004 . 14730073 . 316325 . 10.1104/pp.103.027482 .
- Web site: CBDAS - Cannabidiolic acid synthase precursor - Cannabis sativa (Hemp) - CBDAS gene & protein . UniProt . 26 February 2016.
