Triptolide directly inhibits dCTP pyrophosphatase

Area of Science:

• Natural product chemistry
• Molecular biology
• Biochemistry

Background:

• Triptolide is a natural product with diverse documented biological activities, including antiproliferative and anti-inflammatory effects.
• Despite extensive research on triptolide's effects, its specific intracellular target proteins have remained unidentified.
• Understanding triptolide's molecular targets is crucial for elucidating its mechanisms of action.

Purpose of the Study:

• To identify the direct intracellular target proteins of triptolide.
• To investigate the interaction between triptolide and its potential targets at a molecular level.
• To characterize triptolide as an inhibitor of its identified target protein.

Main Methods:

• Synthesis of a biotinylated photoaffinity derivative of triptolide for target identification.
• Affinity-based pull-down assays to isolate triptolide-binding proteins.
• Biochemical assays to confirm the interaction and enzymatic inhibition of the identified target protein.

Main Results:

• A biotinylated photoaffinity derivative of triptolide was successfully synthesized.
• dCTP pyrophosphatase 1 (DCTPP1) was identified as a triptolide-interacting protein.
• Triptolide was shown to directly interact with and inhibit the enzymatic activity of recombinant DCTPP1.

Conclusions:

• DCTPP1 is a biophysically validated direct target of triptolide.
• Triptolide is the first identified inhibitor of dCTP pyrophosphatase 1.
• This discovery provides a molecular basis for triptolide's biological activities and opens new avenues for therapeutic research.