Selective Inhibitors of Bacterial DNA Adenine Methyltransferases

• Published in: Journal of biomolecular screening Vol. 11; no. 5; pp. 497 - 510
• Main Authors: Mashhoon, Neda, Pruss, Cynthia, Carroll, Michael, Johnson, Paul H., Reich, Norbert O.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.08.2006
• Subjects: binding assays; cell cycle–regulated methyltransferase; DNA (Cytosine-5-)-Methyltransferase 1; DNA (Cytosine-5-)-Methyltransferases - metabolism; DNA adenine methyltransferase; DNA, Bacterial - metabolism; DNA-Binding Proteins - metabolism; Drug Evaluation, Preclinical; Enzyme Inhibitors - metabolism; Enzyme Inhibitors - toxicity; Fluorescence Resonance Energy Transfer; Humans; inhibitors; Inhibitory Concentration 50; Models, Biological; Site-Specific DNA-Methyltransferase (Adenine-Specific) - antagonists & inhibitors; Structure-Activity Relationship; Substrate Specificity; inhibitors; binding assays; DNA adenine methyltransferase; cell cycle–regulated methyltransferase
• ISSN: 2472-5552; 1087-0571; 2472-5560
• DOI: 10.1177/1087057106287933

The authors describe the discovery and characterization of several structural classes of small-molecule inhibitors of bacterial DNA adenine methyltransferases. These enzymes are essential for bacterial virulence (DNA adenine methyltransferase [DAM]) and cell viability (cell cycle–regulated methyltransferase [CcrM]). Using a novel high-throughput fluorescence-based assay and recombinant DAM and CcrM, the authors screened a diverse chemical library. They identified 5 major structural classes of inhibitors composed of more than 350 compounds: cyclopentaquinolines, phenyl vinyl furans, pyrimidine-diones, thiazolidine-4-ones, and phenyl-pyrroles. DNA binding assays were used to identify compounds that interact directly with DNA. Potent compounds selective for the bacterial target were identified, whereas other compounds showed greater selectivity for the mammalian DNA cytosine methyltransferase, Dnmt1. Enzyme inhibition analysis identified mechanistically distinct compounds that interfered with DNA or cofactor binding. Selected compounds demonstrated cell-based efficacy. These small-molecule DNA methyltransferase inhibitors provide useful reagents to probe the role of DNA methylation and may form the basis of developing novel antibiotics.