title: Macrocyclic inhibitors for peptide deformylase: a structure-activity relationship study of the ring size.
abstract: Peptide deformylase (PDF) catalyzes the removal of the N-terminal formyl group from newly synthesized polypeptides in eubacteria. Its essential role in bacterial cells but not in mammalian cells makes it an attractive target for antibacterial drug design. We have previously reported an N-formylhydroxylamine-based, metal-chelating macrocyclic PDF inhibitor, in which the P(1)' and P(3)' side chains are covalently joined. In this work, we have carried out a structure-activity relationship study on the size of the macrocycle and found that 15-17-membered macrocycles are optimal for binding to the PDF active site. Unlike the acyclic compounds, which are simple competitive inhibitors, the cyclic compounds all act as slow-binding inhibitors. As compared to their acyclic counterparts, the cyclic inhibitors displayed 20-50-fold higher potency against the PDF active site (K(I) as low as 70 pM), improved selectivity toward PDF, and improved the metabolic stability in rat plasma. Some of the macrocyclic inhibitors had potent, broad spectrum antibacterial activity against clinically significant Gram-positive and Gram-negative pathogens. These results suggest that the macrocyclic scaffold provides an excellent lead for the development of a new class of antibiotics.
authors.affiliation: Department of Chemistry and Ohio State Biochemistry Program, The Ohio State University, 100 West 18th Avenue, Columbus, Ohio 43210, USA.
authors.forename: Xubo
authors.initials: X
authors.lastname: Hu
authors.forename: Kiet T
authors.initials: KT
authors.lastname: Nguyen
authors.forename: Vernon C
authors.initials: VC
authors.lastname: Jiang
authors.forename: Denene
authors.initials: D
authors.lastname: Lofland
authors.forename: Heinz E
authors.initials: HE
authors.lastname: Moser
authors.forename: Dehua
authors.initials: D
authors.lastname: Pei
mesh_terms: D000581:Amidohydrolases / Q000037:antagonists & inhibitors* / Q000737:chemistry / Q000378:metabolism; D000818:Animals; D000900:Anti-Bacterial Agents / Q000737:chemistry* / Q000494:pharmacology*; D001665:Binding Sites; D004353:Drug Evaluation, Preclinical / Q000379:methods; D004355:Drug Stability; D004791:Enzyme Inhibitors / Q000737:chemistry* / Q000494:pharmacology*; D006571:Heterocyclic Compounds / Q000737:chemistry*; D006801:Humans; D008826:Microbial Sensitivity Tests; D051381:Rats; D013329:Structure-Activity Relationship
chemical_list: D000900:Anti-Bacterial Agents; D004791:Enzyme Inhibitors; D006571:Heterocyclic Compounds; D000581:Amidohydrolases; C084507:peptide deformylase