Inhibitors of bacterial cystathionine beta-lyase: leads for new antimicrobial agents and probes of enzyme structure and function.
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.
Ejim
Linda J
LJ
Antimicrobial Research Centre, McMaster High Throughput Screening Laboratory, Department of Biochemistry and Biomedical Sciences, McMaster University, Ontario L8N 3Z5, Canada.
Blanchard
Jan E
JE
Koteva
Kalinka P
KP
Sumerfield
Rachael
R
Elowe
Nadine H
NH
Chechetto
Jonathan D
JD
Brown
Eric D
ED
Junop
Murray S
MS
Wright
Gerard D
GD
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
D000900:Anti-Bacterial Agents; D000890:Anti-Infective Agents; D000935:Antifungal Agents; D001549:Benzamides; D006834:Hydrazines; D008190:Lyases; C019965:cystathionine beta-lyase