title: Rational design of femtomolar inhibitors of isoleucyl tRNA synthetase from a binding model for pseudomonic acid-A.
abstract: This paper describes the design and characterization of novel inhibitors of IleRS, whose binding affinity approaches the tightest reported for noncovalent inhibition. Compounds were designed from a binding model for the natural product pseudomonic acid-A (PS-A) together with a detailed understanding of the reaction cycle of IleRS and characterization of the mode of binding of the reaction intermediate IleAMP. The interactions of the compounds with IleRS were characterized by inhibition of aminoacylation of tRNA or PP(i)/ATP exchange at supersaturating substrate concentration and by transient kinetics and calorimetry methods. A detailed understanding of the interaction of a comprehensive series of compounds with IleRS allowed the identification of key features and hence the design of exquisitely potent inhibitors. Predictions based on these results have been recently supported by a docking model based on the crystal structure of IleRS with PS-A [Silvian, L. F., Wang J. M., and Steitz T. A. (1999) Science 285 1074-1077].
authors.affiliation: Department of Molecular Recognition, SmithKline Beecham, New Frontiers Science Park, Harlow, Essex, U.K.
authors.forename: M J
authors.initials: MJ
authors.lastname: Brown
authors.forename: L M
authors.initials: LM
authors.lastname: Mensah
authors.forename: M L
authors.initials: ML
authors.lastname: Doyle
authors.forename: N J
authors.initials: NJ
authors.lastname: Broom
authors.forename: N
authors.initials: N
authors.lastname: Osbourne
authors.forename: A K
authors.initials: AK
authors.lastname: Forrest
authors.forename: C M
authors.initials: CM
authors.lastname: Richardson
authors.forename: P J
authors.initials: PJ
authors.lastname: O'Hanlon
authors.forename: A J
authors.initials: AJ
authors.lastname: Pope
mesh_terms: D000900:Anti-Bacterial Agents / Q000737:chemistry* / Q000378:metabolism; D001665:Binding Sites; D002152:Calorimetry, Differential Scanning; D002942:Circular Dichroism; D004791:Enzyme Inhibitors / Q000138:chemical synthesis* / Q000378:metabolism; D004795:Enzyme Stability; D007532:Isoleucine / Q000737:chemistry / Q000378:metabolism; D007533:Isoleucine-tRNA Ligase / Q000037:antagonists & inhibitors* / Q000737:chemistry* / Q000378:metabolism; D007700:Kinetics; D008956:Models, Chemical; D008958:Models, Molecular; D016712:Mupirocin / Q000737:chemistry* / Q000378:metabolism; D013050:Spectrometry, Fluorescence; D013211:Staphylococcus aureus / Q000201:enzymology; D013329:Structure-Activity Relationship; D013816:Thermodynamics
chemical_list: D000900:Anti-Bacterial Agents; D004791:Enzyme Inhibitors; D007532:Isoleucine; D016712:Mupirocin; D007533:Isoleucine-tRNA Ligase