Quantitative NanoProteomics approach for protein complex (QNanoPX) using gold nanoparticle-based DNA probe

Area of Science:

• Biochemistry
• Molecular Biology
• Nanotechnology

Background:

• Affinity pulldown methods are crucial for purifying endogenous protein complexes.
• Nanoparticle probes can improve the efficiency and scope of pulldown assays.
• Characterizing transcriptional complexes requires robust purification techniques.

Purpose of the Study:

• To develop and describe a method for characterizing the estrogen response element (ERE) transcriptional complex.
• To utilize gold nanoparticle-based DNA probes for enhanced affinity purification.
• To combine pulldown with immunoblotting and quantitative proteomics for comprehensive analysis.

Main Methods:

• Fabrication of gold nanoparticle-based DNA probes.
• Preparation of nuclear extracts.
• Affinity purification using the nanoparticle probe.
• Analysis by immunoblotting.
• Sample preparation for quantitative proteomics including trypsin digestion and stable isotope dimethyl labeling.
• Liquid chromatography-mass spectrometry (LC-MS) analysis.

Main Results:

• Successful fabrication and application of gold nanoparticle-DNA probes for ERE complex pulldown.
• Demonstration of combined immunoblotting and LC-MS for detailed characterization.
• Characterization of the transcriptional complex associated with the estrogen response element.

Conclusions:

• The developed gold nanoparticle-based pulldown method is effective for characterizing transcriptional complexes.
• This approach offers an improvement over traditional pulldown techniques.
• The protocol facilitates in-depth analysis of protein-DNA interactions using quantitative proteomics.