Synthesis of (S)-isoprenoid thiodiphosphates as substrates and inhibitors.
Thiolo thiophosphate analogues of isopentenyl diphosphate (IPP), dimethylallyl diphosphate (DMAPP), geranyl diphosphate (GPP), farnesyl diphosphate (FPP), and geranylgeranyl diphosphate (GGPP) were synthesized. Inorganic thiopyrophosphate (SPP(i)) was prepared from trimethyl phosphate in four steps. The tris(tetra-n-butylammonium) salt was then used to convert isopentenyl tosylate to (S)-isopentenyl thiodiphosphate (ISPP). (S)-Dimethylallyl (DMASPP), (S)-geranyl (GSPP), (S)-farnesyl (FSPP), and (S)-geranylgeranyl thiodiphosphate (GGSPP) were prepared from the corresponding bromides in a similar manner. ISPP and GSPP were substrates for avian farnesyl diphosphate synthase (FPPase). Incubation of the enzyme with ISPP and GPP gave FSPP, whereas incubation with IPP and GSPP gave FPP. GSPP was a substantially less reactive than GPP in the chain elongation reaction and was an excellent competitive inhibitor, K(I)(GSPP) = 24.8 microM, of the enzyme. Thus, when ISPP and DMAPP were incubated with FPPase, GSPP accumulated and was only slowly converted to FSPP.
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Department of Chemistry, University of Utah, Salt Lake City, Utah 84112, USA.
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D000818:Animals; D001717:Birds; D002250:Carbon Radioisotopes; D004791:Enzyme Inhibitors / Q000138:chemical synthesis; D045782:Hemiterpenes; D007700:Kinetics; D009943:Organophosphorus Compounds / Q000138:chemical synthesis* / Q000378:metabolism / Q000494:pharmacology; D011106:Polyisoprenyl Phosphates / Q000138:chemical synthesis* / Q000378:metabolism / Q000494:pharmacology; D011755:Pyrophosphatases / Q000037:antagonists & inhibitors*; D012717:Sesquiterpenes
D002250:Carbon Radioisotopes; D004791:Enzyme Inhibitors; D045782:Hemiterpenes; D009943:Organophosphorus Compounds; D011106:Polyisoprenyl Phosphates; D012717:Sesquiterpenes; C004809:isopentenyl pyrophosphate; C004808:farnesyl pyrophosphate; D011755:Pyrophosphatases; C108148:farnesyl pyrophosphatase; C002963:geranylgeranyl pyrophosphate