Protein Domain Specific Covalent Inhibition of Human DNA Polymerase β

Area of Science:

• Biochemistry
• Molecular Biology
• Drug Discovery

Background:

• DNA polymerase β (Pol β) is a bifunctional enzyme crucial for base excision repair.
• Overexpression and mutation of Pol β are linked to various diseases, making it a therapeutic target.
• There is a need for specific inhibitors to modulate Pol β activity.

Purpose of the Study:

• To characterize novel covalent inhibitors of Pol β.
• To investigate the mechanism by which these inhibitors affect Pol β activity.
• To establish a general strategy for developing domain-selective inhibitors of bifunctional polymerases.

Main Methods:

• Synthesis and characterization of two mechanistically inspired covalent inhibitors (1 and 9).
• Enzyme activity assays to measure polymerase and lyase functions.
• Fluorescence anisotropy experiments to assess DNA binding.

Main Results:

• Inhibitors 1 and 9 effectively modified lysine residues in different Pol β active sites.
• Both inhibitors inactivated both polymerase and lyase activities of Pol β.
• Inhibitors 1 and 9 function by preventing DNA binding to Pol β.

Conclusions:

• Inhibitors 1 and 9 demonstrate a novel approach for creating domain-selective inhibitors of bifunctional polymerases.
• These inhibitors can be valuable tools for researching wild-type and mutant Pol β in DNA repair.
• The findings pave the way for developing targeted therapies involving Pol β.