title: Inhibitors of bacterial cystathionine beta-lyase: leads for new antimicrobial agents and probes of enzyme structure and function.
abstract: The biosynthesis of methionine is an attractive antibiotic target given its importance in protein and DNA metabolism and its absence in mammals. We have performed a high-throughput screen of the methionine biosynthesis enzyme cystathionine beta-lyase (CBL) against a library of 50 000 small molecules and have identified several compounds that inhibit CBL enzyme activity in vitro. These hit molecules were of two classes: those that blocked CBL activity with mixed steady-state inhibition and those that covalently interacted with the enzyme at the active site pyridoxal phosphate cofactor with slow-binding inhibition kinetics. We determined the crystal structure of one of the slow-binding inhibitors in complex with CBL and used this structure as a guide in the synthesis of a small, focused library of analogues, some of which had improved enzyme inhibition properties. These studies provide the first lead molecules for antimicrobial agents that target cystathionine beta-lyase in methionine biosynthesis.
authors.affiliation: Antimicrobial Research Centre, McMaster High Throughput Screening Laboratory, Department of Biochemistry and Biomedical Sciences, McMaster University, Ontario L8N 3Z5, Canada.
authors.forename: Linda J
authors.initials: LJ
authors.lastname: Ejim
authors.forename: Jan E
authors.initials: JE
authors.lastname: Blanchard
authors.forename: Kalinka P
authors.initials: KP
authors.lastname: Koteva
authors.forename: Rachael
authors.initials: R
authors.lastname: Sumerfield
authors.forename: Nadine H
authors.initials: NH
authors.lastname: Elowe
authors.forename: Jonathan D
authors.initials: JD
authors.lastname: Chechetto
authors.forename: Eric D
authors.initials: ED
authors.lastname: Brown
authors.forename: Murray S
authors.initials: MS
authors.lastname: Junop
authors.forename: Gerard D
authors.initials: GD
authors.lastname: Wright
mesh_terms: D000900:Anti-Bacterial Agents / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology; D000890:Anti-Infective Agents / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D000935:Antifungal Agents / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology; D001419:Bacteria / Q000201:enzymology*; D001549:Benzamides / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D002176:Candida albicans / Q000187:drug effects; D018360:Crystallography, X-Ray; D004926:Escherichia coli / Q000201:enzymology; D006834:Hydrazines / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D008190:Lyases / Q000037:antagonists & inhibitors* / Q000737:chemistry* / Q000235:genetics; D008826:Microbial Sensitivity Tests; D008958:Models, Molecular; D021281:Quantitative Structure-Activity Relationship; D012485:Salmonella typhi / Q000201:enzymology
chemical_list: D000900:Anti-Bacterial Agents; D000890:Anti-Infective Agents; D000935:Antifungal Agents; D001549:Benzamides; D006834:Hydrazines; D008190:Lyases; C019965:cystathionine beta-lyase