Synthesis and Enzymatic Studies of Isoprenoid Thiolo Bisubstrate Analogues.

Chain elongation prenyltransferases catalyze the addition of the hydrocarbon moiety of allylic isoprenoid diphosphates to the carbon-carbon double bond in isopentenyl diphosphate (IPP) in the primary building reactions in the isoprenoid biosynthetic pathway. Bis-O-diphosphate analogues 3-OPP/OPP, 4-OPP/OPP, and 5-OPP/OPP and bis-thiolodiphosphate bisubstrate analogues 3-SPP/SPP, 4-SPP/SPP, and 5-SPP/SPP were synthesized. The analogues 4-OPP/OPP, 5-OPP/OPP, 4-SPP/SPP, and 5-SPP/SPP were excellent competitive inhibitors of avian farnesyl diphosphate synthase with KI = 1.

Synthesis and enzymatic studies of bisubstrate analogues for farnesyl diphosphate synthase.

Farnesyl diphosphate synthase catalyzes the sequential chain elongation reactions between isopentenyl diphosphate (IPP) and dimethylallyl diphosphate (DMAPP) to form geranyl diphosphate (GPP) and between IPP and GPP to give farnesyl diphosphate (FPP). Bisubstrate analogues containing the allylic and homoallylic substrates were synthesized by joining fragments for IPP and the allylic diphosphates with a C-C bond between the methyl group at C3 in IPP and the Z-methyl group at C3 in DMAPP (3-OPP) and GPP (4-OPP), respectively. These constructs placed substantial limits on the conformational space available to the analogues relative to the two substrates.

Synthesis of deuterium-labeled derivatives of dimethylallyl diphosphate.

Short practical syntheses for five deuterium-labeled derivatives of dimethylallyl diphosphate (DMAPP) useful for enzymological studies are reported. These include the preparation of the C1-labeled derivatives (R)-[1-2H]3-methylbut-2-enyl diphosphate ((R)-[1-2H]1-OPP) and (S)-[1-2H]3-methylbut-2-enyl diphosphate ((S)-[1-2H]1-OPP), the C2-labeled derivative [2-2H]3-methylbut-2-enyl diphosphate ([2-2H]1-OPP), and the methyl-labeled derivatives (E)-[4,4,4-2H3]3-methylbut-2-enyl diphosphate ((E)-[4,4,4-2H3]1-OPP) and (Z)-[4,4,4-2H3]3-methyl-but-2-enyl diphosphate ((Z)-[4,4,4-2H3]1-OPP).