title: Inhibitor Bound Crystal Structures of Bacterial Nitric Oxide Synthase.
abstract: Nitric oxide generated by bacterial nitric oxide synthase (NOS) increases the susceptibility of Gram-positive pathogens Staphylococcus aureus and Bacillus anthracis to oxidative stress, including antibiotic-induced oxidative stress. Not surprisingly, NOS inhibitors also improve the effectiveness of antimicrobials. Development of potent and selective bacterial NOS inhibitors is complicated by the high active site sequence and structural conservation shared with the mammalian NOS isoforms. To exploit bacterial NOS for the development of new therapeutics, recognition of alternative NOS surfaces and pharmacophores suitable for drug binding is required. Here, we report on a wide number of inhibitor-bound bacterial NOS crystal structures to identify several compounds that interact with surfaces unique to the bacterial NOS. Although binding studies indicate that these inhibitors weakly interact with the NOS active site, many of the inhibitors reported here provide a revised structural framework for the development of new antimicrobials that target bacterial NOS. In addition, mutagenesis studies reveal several key residues that unlock access to bacterial NOS surfaces that could provide the selectivity required to develop potent bacterial NOS inhibitors.
authors.affiliation: Departments of †Molecular Biology and Biochemistry, ‡Pharmaceutical Sciences, and §Chemistry, University of California, Irvine, California 92697-3900, United States.|∥Departments of Chemistry and Molecular Biosciences, ⊥Chemistry of Life Processes Institute, #Center for Molecular Innovation and Drug Discovery, Northwestern University, Evanston, Illinois 60208-3113, United States.
authors.forename: Jeffrey K
authors.initials: JK
authors.lastname: Holden
authors.affiliation: Departments of †Molecular Biology and Biochemistry, ‡Pharmaceutical Sciences, and §Chemistry, University of California, Irvine, California 92697-3900, United States.|∥Departments of Chemistry and Molecular Biosciences, ⊥Chemistry of Life Processes Institute, #Center for Molecular Innovation and Drug Discovery, Northwestern University, Evanston, Illinois 60208-3113, United States.
authors.forename: Dillon
authors.initials: D
authors.lastname: Dejam
authors.affiliation: Departments of †Molecular Biology and Biochemistry, ‡Pharmaceutical Sciences, and §Chemistry, University of California, Irvine, California 92697-3900, United States.|∥Departments of Chemistry and Molecular Biosciences, ⊥Chemistry of Life Processes Institute, #Center for Molecular Innovation and Drug Discovery, Northwestern University, Evanston, Illinois 60208-3113, United States.
authors.forename: Matthew C
authors.initials: MC
authors.lastname: Lewis
authors.affiliation: Departments of †Molecular Biology and Biochemistry, ‡Pharmaceutical Sciences, and §Chemistry, University of California, Irvine, California 92697-3900, United States.|∥Departments of Chemistry and Molecular Biosciences, ⊥Chemistry of Life Processes Institute, #Center for Molecular Innovation and Drug Discovery, Northwestern University, Evanston, Illinois 60208-3113, United States.
authors.forename: He
authors.initials: H
authors.lastname: Huang
authors.affiliation: Departments of †Molecular Biology and Biochemistry, ‡Pharmaceutical Sciences, and §Chemistry, University of California, Irvine, California 92697-3900, United States.|∥Departments of Chemistry and Molecular Biosciences, ⊥Chemistry of Life Processes Institute, #Center for Molecular Innovation and Drug Discovery, Northwestern University, Evanston, Illinois 60208-3113, United States.
authors.forename: Soosung
authors.initials: S
authors.lastname: Kang
authors.affiliation: Departments of †Molecular Biology and Biochemistry, ‡Pharmaceutical Sciences, and §Chemistry, University of California, Irvine, California 92697-3900, United States.|∥Departments of Chemistry and Molecular Biosciences, ⊥Chemistry of Life Processes Institute, #Center for Molecular Innovation and Drug Discovery, Northwestern University, Evanston, Illinois 60208-3113, United States.
authors.forename: Qing
authors.initials: Q
authors.lastname: Jing
authors.affiliation: Departments of †Molecular Biology and Biochemistry, ‡Pharmaceutical Sciences, and §Chemistry, University of California, Irvine, California 92697-3900, United States.|∥Departments of Chemistry and Molecular Biosciences, ⊥Chemistry of Life Processes Institute, #Center for Molecular Innovation and Drug Discovery, Northwestern University, Evanston, Illinois 60208-3113, United States.
authors.forename: Fengtian
authors.initials: F
authors.lastname: Xue
authors.affiliation: Departments of †Molecular Biology and Biochemistry, ‡Pharmaceutical Sciences, and §Chemistry, University of California, Irvine, California 92697-3900, United States.|∥Departments of Chemistry and Molecular Biosciences, ⊥Chemistry of Life Processes Institute, #Center for Molecular Innovation and Drug Discovery, Northwestern University, Evanston, Illinois 60208-3113, United States.
authors.forename: Richard B
authors.initials: RB
authors.lastname: Silverman
authors.affiliation: Departments of †Molecular Biology and Biochemistry, ‡Pharmaceutical Sciences, and §Chemistry, University of California, Irvine, California 92697-3900, United States.|∥Departments of Chemistry and Molecular Biosciences, ⊥Chemistry of Life Processes Institute, #Center for Molecular Innovation and Drug Discovery, Northwestern University, Evanston, Illinois 60208-3113, United States.
authors.forename: Thomas L
authors.initials: TL
authors.lastname: Poulos
mesh_terms: D000595:Amino Acid Sequence; D001412:Bacillus subtilis / Q000737:chemistry / Q000201:enzymology*; D018360:Crystallography, X-Ray; D055808:Drug Discovery; D004791:Enzyme Inhibitors / Q000737:chemistry* / Q000494:pharmacology*; D006801:Humans; D008958:Models, Molecular; D008969:Molecular Sequence Data; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors* / Q000737:chemistry* / Q000378:metabolism; D011487:Protein Conformation; D016415:Sequence Alignment; D013203:Staphylococcal Infections / Q000382:microbiology; D013211:Staphylococcus aureus / Q000737:chemistry / Q000201:enzymology*
chemical_list: D004791:Enzyme Inhibitors; D019001:Nitric Oxide Synthase