title: Substrate Fragmentation for the Design of M. tuberculosis CYP121 Inhibitors.
abstract: 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 and speculation into the biological role of the enzyme for Mtb.
authors.affiliation: Department of Chemistry, The University of Cambridge, Lensfield Road, Cambridge, CB2 1EW, UK.
authors.forename: Madeline E
authors.initials: ME
authors.lastname: Kavanagh
authors.affiliation: Department of Chemistry, The University of Cambridge, Lensfield Road, Cambridge, CB2 1EW, UK.
authors.forename: Janine L
authors.initials: JL
authors.lastname: Gray
authors.affiliation: Department of Chemistry, The University of Cambridge, Lensfield Road, Cambridge, CB2 1EW, UK.
authors.forename: Sophie H
authors.initials: SH
authors.lastname: Gilbert
authors.affiliation: Department of Chemistry, The University of Cambridge, Lensfield Road, Cambridge, CB2 1EW, UK.
authors.forename: Anthony G
authors.initials: AG
authors.lastname: Coyne
authors.affiliation: Centre for Synthetic Biology of Fine and Specialty Chemicals (SYNBIOCHEM), Manchester Institute of Biotechnology, Faculty of LifeSciences, The University of Manchester, Manchester, M1 7DN, UK.
authors.forename: Kirsty J
authors.initials: KJ
authors.lastname: McLean
authors.affiliation: Department of Chemistry, The University of Cambridge, Lensfield Road, Cambridge, CB2 1EW, UK.
authors.forename: Holly J
authors.initials: HJ
authors.lastname: Davis
authors.affiliation: Centre for Synthetic Biology of Fine and Specialty Chemicals (SYNBIOCHEM), Manchester Institute of Biotechnology, Faculty of LifeSciences, The University of Manchester, Manchester, M1 7DN, UK.
authors.forename: Andrew W
authors.initials: AW
authors.lastname: Munro
authors.affiliation: Department of Chemistry, The University of Cambridge, Lensfield Road, Cambridge, CB2 1EW, UK. ca26@cam.ac.uk.
authors.forename: Chris
authors.initials: C
authors.lastname: Abell
mesh_terms: D000900:Anti-Bacterial Agents / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D018360:Crystallography, X-Ray; D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism*; D004151:Dipeptides / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D015195:Drug Design; D004791:Enzyme Inhibitors / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D008826:Microbial Sensitivity Tests; D008958:Models, Molecular; D008968:Molecular Conformation; D009169:Mycobacterium tuberculosis / Q000187:drug effects* / Q000201:enzymology; D013329:Structure-Activity Relationship
chemical_list: D000900:Anti-Bacterial Agents; D004151:Dipeptides; D004791:Enzyme Inhibitors; C464825:cytochrome P-450 CYP121; D003577:Cytochrome P-450 Enzyme System
keywords: drug discovery; enzymes; fragment-based methods; substrate analogues; tuberculosis