title: Arginine-containing peptides as potent inhibitors of VIM-2 metallo-β-lactamase.
abstract: BACKGROUND
  Metallo-β-lactamases (MBLs) play an important role in the emergence of microbial resistance to β-lactam antibiotics, and are hence considered targets for the design of novel therapeutics. We here report on the inhibitory effect of peptides containing multiple arginine residues on VIM-2, a clinically important MBL from Pseudomonas aeruginosa.
  
  
  METHODS
  Enzyme kinetic assays in combination with fluorescence spectroscopy and stopped-flow UV-Vis spectrophotometry were utilized to explore the structure-activity relationship of peptides as inhibitors of VIM-2.
  
  
  RESULTS
  Our studies show that the inhibitory potency of the investigated peptides was mainly dependent on the number of arginine residues in the center of the peptide sequence, and on the composition of the N-terminus. The most potent inhibitors were found to curtail enzyme function in the mid-to-low nanomolar range. Salts generally reduced peptide-mediated inhibition. Analysis of the mode of inhibition suggests the peptides to act as mixed-type inhibitors with a higher affinity for the enzyme-substrate complex. Stopped-flow UV-Vis and fluorescence studies revealed the peptides to induce rapid protein aggregation, a phenomenon strongly correlated to the peptides' inhibitory potency. Inhibition of IMP-1 (another subclass B1 MBL) by the peptides was found to be much weaker than that observed with VIM-2, a finding which might be related to subtle molecular differences in the protein surfaces.
  
  
  CONCLUSIONS
  The reported data indicate that arginine-containing peptides can serve as potent, aggregation-inducing inhibitors of VIM-2, and potentially of other MBLs.
  
  
  CONCLUSIONS
  Arginine-containing peptides can be considered as a novel type of potent MBL inhibitors.
authors.affiliation: Department of Chemistry and Biochemistry, Laurentian University, Sudbury, Ontario P3E 2C6, Canada.
authors.forename: Caitlyn M
authors.initials: CM
authors.lastname: Rotondo
authors.affiliation: Department of Chemistry, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada.
authors.forename: Laura
authors.initials: L
authors.lastname: Marrone
authors.affiliation: Department of Chemistry, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada.
authors.forename: Valerie J
authors.initials: VJ
authors.lastname: Goodfellow
authors.affiliation: Department of Chemistry, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada.
authors.forename: Ahmad
authors.initials: A
authors.lastname: Ghavami
authors.affiliation: Department of Chemistry, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada.
authors.forename: Geneviève
authors.initials: G
authors.lastname: Labbé
authors.affiliation: School of Cellular and Molecular Medicine, University of Bristol, Medical Sciences Building, Bristol BS8 1TD, United Kingdom.
authors.forename: James
authors.initials: J
authors.lastname: Spencer
authors.affiliation: Department of Chemistry, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada.
authors.forename: Gary I
authors.initials: GI
authors.lastname: Dmitrienko
authors.affiliation: Department of Chemistry and Biochemistry, Laurentian University, Sudbury, Ontario P3E 2C6, Canada. Electronic address: ssiemann@laurentian.ca.
authors.forename: Stefan
authors.initials: S
authors.lastname: Siemann
mesh_terms: D001120:Arginine; D010455:Peptides / Q000494:pharmacology*; D066329:Protein Aggregates; D013329:Structure-Activity Relationship; D065093:beta-Lactamase Inhibitors / Q000494:pharmacology*; D001618:beta-Lactamases / Q000737:chemistry
chemical_list: D010455:Peptides; D066329:Protein Aggregates; D065093:beta-Lactamase Inhibitors; D001120:Arginine; C409201:beta-lactamase IMP-1; C425108:beta-lactamase bla(vim-2); D001618:beta-Lactamases
keywords: Antibiotic resistance; Metallo-β-lactamases; Peptide inhibitors; Protein aggregation