biostudies-literatureKavanagh MECommonwealth (University of Cambridge) ScholarshipCambridge Commonwealth TrustCambridge Overseas TrustWellcome TrustBiotechnology and Biological Sciences Research CouncilEngineering and Physical Sciences Research Council1924-35https://www.ebi.ac.uk/biostudies/studies/S-EPMC5026067biostudies-literatureUnknown11(17)The cyclo-dipeptide substrates of the essential M. tuberculosis (Mtb) enzyme CYP121 were deconstructed into their component fragments and screened against the enzyme. A number of hits were identified, one of which exhibited an unexpected inhibitor-like binding mode. The inhibitory pharmacophore was elucidated, and fragment binding affinity was rapidly improved by synthetic elaboration guided by the structures of CYP121 substrates. The resulting inhibitors have low micromolar affinity, good predicted physicochemical properties and selectivity for CYP121 over other Mtb P450s. Spectroscopic characterisation of the inhibitors' binding mode provides insight into the effect of weak nitrogen-donor ligands on the P450 heme, an improved understanding of factors governing CYP121-ligand recognition aChemMedChemSubstrate Fragmentation for the Design of M. tuberculosis CYP121 Inhibitors.PMC5026067BB/I019227/1EP/K039520/1GR080083/Z/06BB/I019669/1Gilbert SHMunro AWKavanagh MEMcLean KJAbell CCoyne AGDavis HJGray JLfalseSubstrate Fragmentation for the Design of M. tuberculosis CYP121 Inhibitors.The cyclo-dipeptide substrates of the essential M. tuberculosis (Mtb) enzyme CYP121 were deconstructed into their component fragments and screened against the enzyme. A number of hits were identified, one of which exhibited an unexpected inhibitor-like binding mode. The inhibitory pharmacophore was elucidated, and fragment binding affinity was rapidly improved by synthetic elaboration guided by the structures of CYP121 substrates. The resulting inhibitors have low micromolar affinity, good predicted physicochemical properties and selectivity for CYP121 over other Mtb P450s. Spectroscopic characterisation of the inhibitors' binding mode provides insight into the effect of weak nitrogen-donor ligands on the P450 heme, an improved understanding of factors governing CYP121-ligand recognition a2016-01-01T00:00:00Z2016 Sep2026-05-03T19:31:43.833Z2026-04-07T19:33:32.085ZS-EPMC50260672743247510.1002/cmdc.201600248