2 research outputs found
Peptide-Based Covalent Inhibitors Bearing Mild Electrophiles to Target a Conserved His Residue of the Bacterial Sliding Clamp
Peptide-based covalent
inhibitors targeted to nucleophilic protein
residues have recently emerged as new modalities to target proteināprotein
interactions (PPIs) as they may provide some benefits over more classic
competitive inhibitors. Covalent inhibitors are generally targeted
to cysteine, the most intrinsically reactive amino acid residue, and
to lysine, which is more abundant at the surface of proteins but much
less frequently to histidine. Herein, we report the structure-guided
design of targeted covalent inhibitors (TCIs) able to bind covalently
and selectively to the bacterial sliding clamp (SC), by reacting with
a well-conserved histidine residue located on the edge of the peptide-binding
pocket. SC is an essential component of the bacterial DNA replication
machinery, identified as a promising target for the development of
new antibacterial compounds. Thermodynamic and kinetic analyses of
ligands bearing different mild electrophilic warheads confirmed the
higher efficiency of the chloroacetamide compared to Michael acceptors.
Two high-resolution X-ray structures of covalent inhibitorāSC
adducts were obtained, revealing the canonical orientation of the
ligand and details of covalent bond formation with histidine. Proteomic
studies were consistent with a selective SC engagement by the chloroacetamide-based
TCI. Finally, the TCI of SC was substantially more active than the
parent noncovalent inhibitor in an in vitro SC-dependent DNA synthesis
assay, validating the potential of the approach to design covalent
inhibitors of proteināprotein interactions targeted to histidine
Peptide-Based Covalent Inhibitors Bearing Mild Electrophiles to Target a Conserved His Residue of the Bacterial Sliding Clamp
Peptide-based covalent
inhibitors targeted to nucleophilic protein
residues have recently emerged as new modalities to target proteināprotein
interactions (PPIs) as they may provide some benefits over more classic
competitive inhibitors. Covalent inhibitors are generally targeted
to cysteine, the most intrinsically reactive amino acid residue, and
to lysine, which is more abundant at the surface of proteins but much
less frequently to histidine. Herein, we report the structure-guided
design of targeted covalent inhibitors (TCIs) able to bind covalently
and selectively to the bacterial sliding clamp (SC), by reacting with
a well-conserved histidine residue located on the edge of the peptide-binding
pocket. SC is an essential component of the bacterial DNA replication
machinery, identified as a promising target for the development of
new antibacterial compounds. Thermodynamic and kinetic analyses of
ligands bearing different mild electrophilic warheads confirmed the
higher efficiency of the chloroacetamide compared to Michael acceptors.
Two high-resolution X-ray structures of covalent inhibitorāSC
adducts were obtained, revealing the canonical orientation of the
ligand and details of covalent bond formation with histidine. Proteomic
studies were consistent with a selective SC engagement by the chloroacetamide-based
TCI. Finally, the TCI of SC was substantially more active than the
parent noncovalent inhibitor in an in vitro SC-dependent DNA synthesis
assay, validating the potential of the approach to design covalent
inhibitors of proteināprotein interactions targeted to histidine