Cyclic sample pooling using two-dimensional liquid chromatography system enhances coverage in shotgun proteomics

Area of Science:

• Proteomics
• Analytical Chemistry
• Biochemistry

Background:

• Shotgun proteomics using LC-ESI-MS/MS is crucial for large-scale protein identification.
• Achieving deeper proteome coverage remains a challenge in current proteomic workflows.
• Two-dimensional liquid chromatography (2D-LC) enhances separation but can be limited by sample complexity and resolving power.

Purpose of the Study:

• To introduce a novel cyclic sample pooling technique for 2D LC-ESI-MS shotgun proteomics.
• To enhance proteome coverage and improve the resolving power of LC-ESI-MS/MS analyses.
• To provide a more efficient method for deep proteome profiling.

Main Methods:

• Development of a cyclic sample pooling strategy integrated into a 2D LC setup.
• Utilizing low pH reversed-phase (RP) LC with trifluoroacetic acid in the first dimension.
• Employing low pH RP-LC with formic acid in the second dimension following cyclic pooling of eluates.

Main Results:

• The cyclic sample pooling technique significantly increases proteome coverage compared to conventional methods.
• The enhanced 2D LC-ESI-MS protocol demonstrates substantially higher resolving power.
• The method is suitable for deep and comprehensive LC-ESI-MS/MS shotgun proteomics.

Conclusions:

• Cyclic sample pooling is an effective strategy to enhance proteome coverage in 2D LC-ESI-MS.
• The developed protocol offers improved resolving power for advanced shotgun proteomics.
• This technique represents a significant advancement for deep proteome analysis.