IspG (also called GcpE) is an oxygen-sensitive [4Fe-4S] enzyme catalyzing the penultimate step of the methylerythritol phosphate (MEP) pathway, a validated target for drug development. It converts 2-C-methyl-d-erythritol-2,4-cyclo-diphosphate (MEcPP) into (E)-4-hydroxy-3-methyl-but-2-enyl-1-diphosphate (HMBPP). The reaction, assimilated to a reductive dehydration, involves redox partners responsible for the formal transfer of two electrons to substrate MEcPP. The 2-vinyl analogue of MEcPP was designed to generate conjugated species during enzyme catalysis, with the aim of providing new reactive centers to be covalently trapped by neighboring amino acid residues. The synthesized substrate analogue displayed irreversible inhibition towards IspG. Furthermore, we have shown that electron transfer occurs prior to inhibition; this might designate conjugated intermediates as probable affinity tags through covalent interaction at the catalytic site. This is the first report of an irreversible inhibitor of the IspG metalloenzyme.
The Cover Feature illustrates the rational design of a substrate analogue has afforded the first irreversible inhibitor of an IspG enzyme, a target for the development of new drugs to fight antimicrobial resistance. Inspired by the structural features of the natural substrate and by mechanistic aspects, we introduced a vinyl substituent to generate conjugated species during enzyme catalysis. Inhibition might occur through covalent interaction at the catalytic site.
V. Herrscher,C. Witjaksono,M. Buchotte,C. Ferret,F. Massicot,J.-L. Vasse,F. Borel,J.-B. Behr, M. Seemann
Irreversible inhibition of IspG, a target for the development of new antimicrobials, by a 2-vinyl analogue of its MEcPP substrate
Chem. Eur. J. 2022- DOI: https://doi.org/10.1002/chem.202200241
Cover feature : https://chemistry-europe.onlinelibrary.wiley.com/doi/full/10.1002/chem.202201234
Myriam SEEMANN, équipe CBAT, Institut de Chimie (UMR 7177).