Farnesyl diphosphate analogues with omega-bioorthogonal azide and alkyne functional groups for protein farnesyl transferase-catalyzed ligation reactions

Abstract

Eleven farnesyl diphosphate analogues, which contained omega-azide or alkyne substituents suitable for bioorthogonal Staudinger and Huisgen [3 + 2] cycloaddition coupling reactions, were synthesized. The analogues were evaluated as substrates for the alkylation of peptide cosubstrates by yeast protein farnesyl transferase. Five of the diphosphates were good alternative substrates for farnesyl diphosphate (FPP). Steady-state kinetic constants were measured for the active compounds, and the products were characterized by HPLC and LC-MS. Two of the analogues gave steady-state kinetic parameters (kcat and Km) very similar to those of the natural substrate.

Figure 1

Reactions catalyzed by PFTase and PGGTase-I.

Figure 2

Structures of azido and alkyne FPP analogues

Scheme 1

Synthesis of aldehyde 13-OAc and 13-OTBS

Scheme 2

Synthesis of alcohols 15-OAc and 16-OAc and aldehyde 17-OAc

Scheme 3

Synthesis of aldehydes 19-OAc and 19-OTBS

Scheme 4

Synthesis of azide analogues 1-OPP and 2-OPP

Scheme 5

Synthesis of azide analogue 3-OPP

Scheme 6

Synthesis of azide analogues 4-OPP, 5-OPP and 6-OPP

Scheme 7

Synthesis of alkynyl analogues 7-OPP and 9-OPP

Scheme 8

Synthesis of alkynyl analogues 8-OPP and 10-OPP

Scheme 9

Synthesis of alkynyl analogue 11-OPP

Scheme 10

1-OPP azide equilibrium

Scheme 11

Farnesylation of DansylGCVIA with FPP analogues