Inhibition and structure-activity studies of methionine hydroxamic acid derivatives with bacterial peptide...

Area of Science:

• Biochemistry
• Microbiology
• Enzymology

Background:

• Posttranslational deformylation of N-formyl-Met-polypeptides by peptide deformylase is vital for bacterial growth.
• Peptide deformylase (PDF) is a metalloenzyme and a validated target for antibacterial drug development.

Purpose of the Study:

• To investigate the inhibitory potential of methionine hydroxamic acid derivatives against bacterial peptide deformylase.
• To elucidate the binding mode of these inhibitors within the enzyme's active site.

Main Methods:

• Enzyme inhibition assays using recombinant Escherichia coli peptide deformylase (with zinc or cobalt).
• Spectroscopic analysis (UV-Vis) to study inhibitor binding.
• Kinetic studies to determine inhibition constants.

Main Results:

• Methionine hydroxamic acid and hydrazide derivatives inhibited both zinc- and cobalt-substituted E. coli PDF.
• Spectral changes indicated the formation of a pentacoordinate metal complex upon inhibitor binding, similar to actinonin.
• Data suggested inhibitors bind in a reverse orientation within the active site compared to natural substrates.
• Second-generation N-substituted methionyl hydroxamic acids exhibited enhanced inhibitory potency.

Conclusions:

• Methionine derivatives are effective inhibitors of bacterial peptide deformylase.
• The binding mode involves a reverse orientation in the active site.
• These findings provide a foundation for designing potent and selective PDF inhibitors as novel antibacterial agents.