title: Partial purification and characterization of two sesquiterpene cyclases from sage (Salvia officinalis) which catalyze the respective conversion of farnesyl pyrophosphate to humulene and caryophyllene.
abstract: Humulene cyclase and caryophyllene cyclase, two enzymes which catalyze the cyclization of farnesyl pyrophosphate to the respective sesquiterpene olefins, have been partially purified from the supernatant fraction of a sage (Salvia officinalis) leaf epidermis extract and separated from each other by a combination of hydrophobic interaction, gel filtration, and ion-exchange chromatography. The molecular weight of both cyclases was estimated by gel filtration to be 57,000 and both cyclases exhibited a pH optimum of 6.5 and preferred Mg2+ (Km approximately 1.5 mM) as the required divalent metal cation. Both enzymes possessed a Km of about 1.7 microM for farnesyl pyrophosphate, were strongly inhibited by p-hydroxymercuribenzoate, and exhibited comparable sensitivities to a variety of other potential inhibitors. The properties of the two sesquiterpene olefin cyclases, which are the first from a higher plant source to be examined in detail, were very similar to each other and to other monoterpene, sesquiterpene, and diterpene cyclases previously described.
authors: Institute of Biological Chemistry, Washington State University, Pullman 99164-6340.
authors: S S
authors: SS
authors: Dehal
authors: R
authors: R
authors: Croteau
mesh_terms: D002850:Chromatography, Gel; D002852:Chromatography, Ion Exchange; D003500:Cyclization; D007535:Isomerases; D000081222:Monocyclic Sesquiterpenes; D010944:Plants / Q000201:enzymology*; D000081223:Polycyclic Sesquiterpenes; D011106:Polyisoprenyl Phosphates / Q000378:metabolism*; D012717:Sesquiterpenes / Q000378:metabolism*; D014166:Transferases / Q000302:isolation & purification*
chemical_list: D000081222:Monocyclic Sesquiterpenes; D000081223:Polycyclic Sesquiterpenes; D011106:Polyisoprenyl Phosphates; D012717:Sesquiterpenes; C042686:humulene; C004808:farnesyl pyrophosphate; C024714:caryophyllene; D014166:Transferases; D007535:Isomerases; C055295:caryophyllene cyclase; C055294:humulene cyclase