alpha-farnesene and farnesyl-pyrophosphate

Farnesol, derived from farnesyl pyrophosphate in the sterols biosynthetic pathway, is a molecule with three unsaturations and four possible isomers.. The study involved the addition of exogenous. Exogenously added. The findings collectively offer the first insights into the mechanism of action of farnesol on

Topics: Candida albicans; Farnesol; Leishmania; Leishmania mexicana; Sterols

A recombinant alpha-farnesene synthase from apple (Malus x domestica), expressed in Escherichia coli, showed features not previously reported. Activity was enhanced 5-fold by K(+) and all four isomers of alpha-farnesene, as well as beta-farnesene, were produced from an isomeric mixture of farnesyl diphosphate (FDP). Monoterpenes, linalool, (Z)- and (E)-beta-ocimene and beta-myrcene, were synthesised from geranyl diphosphate (GDP), but at 18% of the optimised rate for alpha-farnesene synthesis from FDP. Addition of K(+) reduced monoterpene synthase activity. The enzyme also produced alpha-farnesene by a reaction involving coupling of GDP and isoprenyl diphosphate but at <1% of the rate with FDP. Mutagenesis of active site aspartate residues removed sesquiterpene, monoterpene and prenyltransferase activities suggesting catalysis through the same active site. Phylogenetic analysis clusters this enzyme with isoprene synthases rather than with other sesquiterpene synthases, suggesting that it has evolved differently from other plant sesquiterpene synthases. This is the first demonstration of a sesquiterpene synthase possessing prenyltransferase activity.

Topics: Alkyl and Aryl Transferases; Binding Sites; Dimethylallyltranstransferase; Gas Chromatography-Mass Spectrometry; Guanosine Diphosphate; Inosine Diphosphate; Magnoliopsida; Malus; Metals; Monoterpenes; Mutagenesis; Mutant Proteins; Phylogeny; Polyisoprenyl Phosphates; Pyrophosphatases; Recombinant Proteins; Sesquiterpenes; Time Factors