Substrate Specificities of <i>E</i>-and <i>Z</i>-Farnesyl Diphosphate Synthases with Artificial Substrates

Abstract

Here, to assess substrate specificities of E-and Z-farnesyl diphosphate synthases from Bacillus stearothermophilus and Thermobifida fusca, we examined the reactivities of isopentenyl diphosphate homologs having an alkyl group at the 3-position. E-and Z-FPP synthase reactions of geranyl diphosphate (GPP) with 3-ethylisopentenyl diphosphate produced E-and Z-3-ethylfarnesyl diphosphates (yield: 70.8%, and 11.3%, respectively). The E-FPP synthase reaction of GPP with 3-propylisopentenyl diphosphate produced E-3-propylfarnesyl diphosphate (yield: 40.1%); however, when reacting GPP with 3-propylisopentenyl diphosphate by Z-FPP synthase reaction, only trace product was acquired. Further, neither E-nor Z-FPP synthase reaction of GPP with 3-butylisopentanyl diphosphate produced any product.

Extension of the Terpene Chemical Space: the Very First Biosynthetic Steps

“…Using 3-ethyl-but-3-enyl-1-diphosphate as a substrate, [47][48][49] the FPPS of the thermotolerant bacterium Bacillus stearothermophilus was able to generate, with GPP as a starting unit and a good yield (Scheme 9), the FPP homologue carrying a C-3 ethyl substituent. [49] The same enzyme was found to be superior [50] to pig liver FPPS [51,52] in terms of final yield when tested with (3Z)-3-methyl-pent-3-enyl-1-diphosphate and (3E)-3-methyl-pent-3enyl-1-diphosphate. The characteristic of these two compounds is that if they act as FPPS substrates, the product formed is chiral.…”