Alpha-bisabolene synthase

{{Short description|Enzyme}}

{{Infobox enzyme

| Name = α-isabolene synthase

| EC_number = 4.2.3.38

| CAS_number =

| GO_code =

| image =

| width =

| caption =

}}

α-Bisabolene synthase (EC 4.2.3.38, bisabolene synthase) is an enzyme with systematic name (2E,6E)-farnesyl-diphosphate diphosphate-lyase ((E)-α-bisabolene-forming).{{cite journal | vauthors = Bohlmann J, Crock J, Jetter R, Croteau R | title = Terpenoid-based defenses in conifers: cDNA cloning, characterization, and functional expression of wound-inducible (E)-alpha-bisabolene synthase from grand fir (Abies grandis) | journal = Proceedings of the National Academy of Sciences of the United States of America | volume = 95 | issue = 12 | pages = 6756–61 | date = June 1998 | pmid = 9618485 | pmc = 22624 | doi = 10.1073/pnas.95.12.6756 | bibcode = 1998PNAS...95.6756B | doi-access = free }}

This enzyme catalyses the following chemical reaction:

: (2E,6E)-farnesyl diphosphate $\backslash rightleftharpoons$ (E)-α-bisabolene + diphosphate

This synthase requires a divalent cation cofactor (Mg²⁺ or, to a lesser extent, Mn²⁺) to neutralize the negative charge of the diphosphate leaving group.