title: Rickettsia prowazekii methionine aminopeptidase as a promising target for the development of antibacterial agents.
abstract: Methionine aminopeptidase (MetAP) is a class of ubiquitous enzymes essential for the survival of numerous bacterial species. These enzymes are responsible for the cleavage of N-terminal formyl-methionine initiators from nascent proteins to initiate post-translational modifications that are often essential to proper protein function. Thus, inhibition of MetAP activity has been implicated as a novel antibacterial target. We tested this idea in the present study by targeting the MetAP enzyme in the obligate intracellular pathogen Rickettsia prowazekii. We first identified potent RpMetAP inhibitory species by employing an in vitro enzymatic activity assay. The molecular docking program AutoDock was then utilized to compare published crystal structures of inhibited MetAP species to docked poses of RpMetAP. Based on these in silico and in vitro screens, a subset of 17 compounds was tested for inhibition of R. prowazekii growth in a pulmonary vascular endothelial cell (EC) culture infection model system. All compounds were tested over concentration ranges that were determined to be non-toxic to the ECs and 8 of the 17 compounds displayed substantial inhibition of R. prowazekii growth. These data highlight the therapeutic potential for inhibiting RpMetAP as a novel antimicrobial strategy and set the stage for future studies in pre-clinical animal models of infection.
authors.affiliation: Department of Chemistry and Biochemistry, Northern Illinois University, 1425 W. Lincoln Hwy, DeKalb, IL 60115, USA.
authors.forename: Travis R
authors.initials: TR
authors.lastname: Helgren
authors.affiliation: Department of Chemistry and Biochemistry, Northern Illinois University, 1425 W. Lincoln Hwy, DeKalb, IL 60115, USA.
authors.forename: Congling
authors.initials: C
authors.lastname: Chen
authors.affiliation: Department of Chemistry and Biochemistry, Northern Illinois University, 1425 W. Lincoln Hwy, DeKalb, IL 60115, USA.
authors.forename: Phumvadee
authors.initials: P
authors.lastname: Wangtrakuldee
authors.affiliation: Beryllium Discovery Corp., 7869 NE Day Road West, Bainbridge Island, WA 98110, USA; Seattle Structural Genomics Center for Infectious Disease (SSGCID), Seattle, WA, USA.
authors.forename: Thomas E
authors.initials: TE
authors.lastname: Edwards
authors.affiliation: Center for Infectious Disease Research, Formerly Seattle Biomedical Research Institute, 307 Westlake Avenue N., Seattle, WA 98109, USA; Seattle Structural Genomics Center for Infectious Disease (SSGCID), Seattle, WA, USA.
authors.forename: Bart L
authors.initials: BL
authors.lastname: Staker
authors.affiliation: Beryllium Discovery Corp., 7869 NE Day Road West, Bainbridge Island, WA 98110, USA; Seattle Structural Genomics Center for Infectious Disease (SSGCID), Seattle, WA, USA.
authors.forename: Jan
authors.initials: J
authors.lastname: Abendroth
authors.affiliation: Molecular Biophysics and Integrated Bioimaging, Berkeley Center for Structural Biology, Ernest Orlando Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA.
authors.forename: Banumathi
authors.initials: B
authors.lastname: Sankaran
authors.affiliation: Department of Microbiology and Immunology and The Center for Lung Biology, University of South Alabama College of Medicine, Laboratory of Infectious Diseases, 307 North University Blvd, Mobile, AL 36688, USA.
authors.forename: Nicole A
authors.initials: NA
authors.lastname: Housley
authors.affiliation: Center for Infectious Disease Research, Formerly Seattle Biomedical Research Institute, 307 Westlake Avenue N., Seattle, WA 98109, USA; Seattle Structural Genomics Center for Infectious Disease (SSGCID), Seattle, WA, USA; Department of Global Health and Department of Biomedical Informatics and Medical Education, University of Washington, Seattle, WA 98195, USA.
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Myler
authors.affiliation: Department of Microbiology and Immunology and The Center for Lung Biology, University of South Alabama College of Medicine, Laboratory of Infectious Diseases, 307 North University Blvd, Mobile, AL 36688, USA.
authors.forename: Jonathon P
authors.initials: JP
authors.lastname: Audia
authors.affiliation: Department of Chemistry and Biochemistry, Northern Illinois University, 1425 W. Lincoln Hwy, DeKalb, IL 60115, USA.
authors.forename: James R
authors.initials: JR
authors.lastname: Horn
authors.affiliation: Department of Chemistry and Biochemistry, Northern Illinois University, 1425 W. Lincoln Hwy, DeKalb, IL 60115, USA. Electronic address: thagen@niu.edu.
authors.forename: Timothy J
authors.initials: TJ
authors.lastname: Hagen
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D042783:Endothelial Cells / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D063208:Methionyl Aminopeptidases / Q000037:antagonists & inhibitors* / Q000378:metabolism; D008826:Microbial Sensitivity Tests; D062105:Molecular Docking Simulation; D015394:Molecular Structure; D011651:Pulmonary Artery / Q000187:drug effects; D051381:Rats; D012283:Rickettsia prowazekii / Q000187:drug effects* / Q000201:enzymology; D013329:Structure-Activity Relationship
chemical_list: D000900:Anti-Bacterial Agents; D004791:Enzyme Inhibitors; D063208:Methionyl Aminopeptidases
keywords: Epidemic typhus; Inhibition; Lung endothelial cells; MetAP; Metalloenzyme; Methionine aminopeptidase; Rickettsia prowazekii