title: Selectivity of Pyridone- and Diphenyl Ether-Based Inhibitors for the Yersinia pestis FabV Enoyl-ACP Reductase.
abstract: The enoyl-ACP reductase (ENR) catalyzes the last reaction in the elongation cycle of the bacterial type II fatty acid biosynthesis (FAS-II) pathway. While the FabI ENR is a well-validated drug target in organisms such as Mycobacterium tuberculosis and Staphylococcus aureus, alternate ENR isoforms have been discovered in other pathogens, including the FabV enzyme that is the sole ENR in Yersinia pestis (ypFabV). Previously, we showed that the prototypical ENR inhibitor triclosan was a poor inhibitor of ypFabV and that inhibitors based on the 2-pyridone scaffold were more potent [Hirschbeck, M. (2012) Structure 20 (1), 89-100]. These studies were performed with the T276S FabV variant. In the work presented here, we describe a detailed examination of the mechanism and inhibition of wild-type ypFabV and the T276S variant. The T276S mutation significantly reduces the affinity of diphenyl ether inhibitors for ypFabV (20-fold → 100-fold). In addition, while T276S ypFabV generally displays an affinity for 2-pyridone inhibitors higher than that of the wild-type enzyme, the 4-pyridone scaffold yields compounds with similar affinity for both wild-type and T276S ypFabV. T276 is located at the N-terminus of the helical substrate-binding loop, and structural studies coupled with site-directed mutagenesis reveal that alterations in this residue modulate the size of the active site portal. Subsequently, we were able to probe the mechanism of time-dependent inhibition in this enzyme family by extending the inhibition studies to include P142W ypFabV, a mutation that results in a gain of slow-onset inhibition for the 4-pyridone PT156.
authors.forename: Carla
authors.initials: C
authors.lastname: Neckles
authors.affiliation: Rudolf Virchow Center for Experimental Biomedicine, Institute for Structural Biology, University of Würzburg , D-97080 Würzburg, Germany.
authors.forename: Annica
authors.initials: A
authors.lastname: Pschibul
authors.forename: Cheng-Tsung
authors.initials: CT
authors.lastname: Lai
authors.affiliation: Rudolf Virchow Center for Experimental Biomedicine, Institute for Structural Biology, University of Würzburg , D-97080 Würzburg, Germany.
authors.forename: Maria
authors.initials: M
authors.lastname: Hirschbeck
authors.affiliation: Rudolf Virchow Center for Experimental Biomedicine, Institute for Structural Biology, University of Würzburg , D-97080 Würzburg, Germany.
authors.forename: Jochen
authors.initials: J
authors.lastname: Kuper
authors.forename: Shabnam
authors.initials: S
authors.lastname: Davoodi
authors.forename: Junjie
authors.initials: J
authors.lastname: Zou
authors.forename: Nina
authors.initials: N
authors.lastname: Liu
authors.forename: Pan
authors.initials: P
authors.lastname: Pan
authors.forename: Sonam
authors.initials: S
authors.lastname: Shah
authors.forename: Fereidoon
authors.initials: F
authors.lastname: Daryaee
authors.forename: Gopal R
authors.initials: GR
authors.lastname: Bommineni
authors.affiliation: William A. Shine Great Neck South High School , Great Neck, New York 11020, United States.
authors.forename: Cristina
authors.initials: C
authors.lastname: Lai
authors.forename: Carlos
authors.initials: C
authors.lastname: Simmerling
authors.affiliation: Rudolf Virchow Center for Experimental Biomedicine, Institute for Structural Biology, University of Würzburg , D-97080 Würzburg, Germany.
authors.forename: Caroline
authors.initials: C
authors.lastname: Kisker
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Tonge
mesh_terms: D002384:Catalysis; D020134:Catalytic Domain; D003460:Crystallization; D018360:Crystallography, X-Ray; D050753:Enoyl-(Acyl-Carrier-Protein) Reductase (NADH) / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D008958:Models, Molecular; D056004:Molecular Dynamics Simulation; D016297:Mutagenesis, Site-Directed; D009154:Mutation / Q000235:genetics; D009243:NAD / Q000378:metabolism; D010647:Phenyl Ethers / Q000737:chemistry*; D011485:Protein Binding; D011487:Protein Conformation; D011728:Pyridones / Q000737:chemistry*; D015010:Yersinia pestis / Q000201:enzymology*
chemical_list: D004791:Enzyme Inhibitors; D010647:Phenyl Ethers; D011728:Pyridones; D009243:NAD; D050753:Enoyl-(Acyl-Carrier-Protein) Reductase (NADH)