title: Disruption of insect isoprenoid biosynthesis with pyridinium bisphosphonates.
abstract: Farnesyl diphosphate synthase (FPPS) catalyzes the condensation of the non-allylic diphosphate, isopentenyl diphosphate (IPP; C5), with the allylic diphosphate primer dimethylallyl diphosphate (DMAPP; C5) to generate the C15 prenyl chain (FPP) used for protein prenylation as well as sterol and terpene biosynthesis. Here, we designed and prepared a series of pyridinium bisphosphonate (PyrBP) compounds, with the aim of selectively inhibiting FPPS of the lepidopteran insect order. FPPSs of Drosophila melanogaster and the spruce budworm, Choristoneura fumiferana, were inhibited by several PyrBPs, and as hypothesized, larger bisphosphonates were more selective for the lepidopteran protein and completely inactive towards dipteran and vertebrate FPPSs. Cell growth of a D. melanogaster cell line was adversely affected by exposure to PyrPBs that were strongly inhibitory to insect FPPS, although their effect was less pronounced than that observed upon exposure to the electron transport disrupter, chlorfenapyr. To assess the impact of PyrBPs on lepidopteran insect growth and development, we performed feeding and topical studies, using the tobacco hornworm, Manduca sexta, as our insect model. The free acid form of a PyrBP and a known bisphosphonate inhibitor of vertebrate FPPS, alendronate, had little to no effect on larval M. sexta; however, the topical application of more lipophilic ester PyrBPs caused decreased growth, incomplete larval molting, cuticle darkening at the site of application, and for those insects that survived, the formation of larval-pupal hybrids. To gain a better understanding of the structural differences that produce selective lepidopteran FPPS inhibition, homology models of C. fumiferana and D. melanogaster FPPS (CfFPPS2, and DmFPPS) were prepared. Docking of substrates and PyrBPs demonstrates that differences at the -3 and -4 positions relative to the first aspartate rich motif (FARM) are important factors in the ability of the lepidopteran enzyme to produce homologous isoprenoid structure and to be selectively inhibited by larger PyrBPs.
authors.affiliation: Department of Chemistry, The College of New Jersey, P.O. Box 7718, Ewing, NJ 08628, USA. Electronic address: sen@tcnj.edu.
authors.forename: Stephanie E
authors.initials: SE
authors.lastname: Sen
authors.affiliation: Department of Chemistry, The College of New Jersey, P.O. Box 7718, Ewing, NJ 08628, USA.
authors.forename: Lyndsay
authors.initials: L
authors.lastname: Wood
authors.affiliation: Department of Chemistry, The College of New Jersey, P.O. Box 7718, Ewing, NJ 08628, USA.
authors.forename: Reshma
authors.initials: R
authors.lastname: Jacob
authors.affiliation: Department of Chemistry, The College of New Jersey, P.O. Box 7718, Ewing, NJ 08628, USA.
authors.forename: Alisa
authors.initials: A
authors.lastname: Xhambazi
authors.affiliation: Department of Chemistry, The College of New Jersey, P.O. Box 7718, Ewing, NJ 08628, USA.
authors.forename: Britanny
authors.initials: B
authors.lastname: Pease
authors.affiliation: Department of Chemistry, The College of New Jersey, P.O. Box 7718, Ewing, NJ 08628, USA.
authors.forename: Alexis
authors.initials: A
authors.lastname: Jones
authors.affiliation: Department of Chemistry, The College of New Jersey, P.O. Box 7718, Ewing, NJ 08628, USA.
authors.forename: Taylor
authors.initials: T
authors.lastname: Horsfield
authors.affiliation: Department of Chemistry, The College of New Jersey, P.O. Box 7718, Ewing, NJ 08628, USA.
authors.forename: Alice
authors.initials: A
authors.lastname: Lin
authors.affiliation: Natural Resources Canada, Canadian Forest Service, Laurentian Forestry Centre, 1055 du P.E.P.S., C.P. 10380, Stn. Sainte-Foy, Quebec City, QC G1V 4C7, Canada.
authors.forename: Michel
authors.initials: M
authors.lastname: Cusson
mesh_terms: D000818:Animals; D002460:Cell Line; D004164:Diphosphonates / Q000138:chemical synthesis / Q000494:pharmacology*; D004331:Drosophila melanogaster / Q000187:drug effects* / Q000378:metabolism; D051228:Geranyltranstransferase / Q000037:antagonists & inhibitors / Q000378:metabolism; D007814:Larva / Q000187:drug effects / Q000378:metabolism; D007915:Lepidoptera / Q000187:drug effects* / Q000378:metabolism; D018402:Manduca; D062105:Molecular Docking Simulation; D017434:Protein Structure, Tertiary; D011726:Pyridinium Compounds / Q000138:chemical synthesis / Q000494:pharmacology*; D013329:Structure-Activity Relationship; D013552:Swine; D013729:Terpenes / Q000378:metabolism*
chemical_list: D004164:Diphosphonates; D011726:Pyridinium Compounds; D013729:Terpenes; D051228:Geranyltranstransferase
keywords: Bisphosphonate; Farnesyl diphosphate synthase; Homology modeling; Inhibitor; Topical studies