Trapping mammalian protein complexes in viral particles

Area of Science:

• Molecular Biology
• Biochemistry
• Proteomics

Background:

• Cell lysis in mass spectrometry can disrupt protein complexes.
• Current methods like cross-linking and proximity labeling aim to mitigate lysis effects.
• A need exists for techniques that preserve native protein complex integrity.

Purpose of the Study:

• To develop a novel method for protein complex analysis that avoids cell lysis.
• To preserve the native structure and interactions of protein complexes during purification.
• To identify known and novel protein-protein interactions using mass spectrometry.

Main Methods:

• Developed Virotrap, a viral particle sorting approach.
• Fused bait proteins to HIV-1 GAG to form virus-like particles (VLPs) in mammalian cells.
• Utilized an efficient VLP enrichment protocol for purification and mass spectrometry analysis.

Main Results:

• Virotrap successfully obviates the need for cell homogenization, preserving protein complexes.
• Detected known binary protein interactions and identified novel interaction partners via mass spectrometry.
• Identified stimulus-dependent interactions and trapped protein partners for small molecules.

Conclusions:

• Virotrap is an effective method for studying protein complexes without lysis.
• It preserves protein complex integrity, enabling the discovery of novel interactions.
• Virotrap complements existing techniques for protein complex analysis.