Online dual gradient reversed-phase/porous graphitized carbon nanoHPLC for proteomic applications

Area of Science:

• Proteomics and Glycoproteomics
• Analytical Chemistry
• Chromatography

Background:

• Proteolytic peptide mixture analysis is crucial in proteomics.
• Reversed-phase liquid chromatography (RPLC) is standard but misses hydrophilic compounds.
• Undersampling during mass spectrometry limits current RPLC methods.

Purpose of the Study:

• To develop an improved analytical setup for broader compound accessibility in proteomics and glycoproteomics.
• To overcome the limitations of conventional reversed-phase nanoHPLC for hydrophilic analytes.
• To enable comprehensive analysis of complex biological mixtures.

Main Methods:

• A dual gradient system integrating RPLC and porous graphitic carbon (PGC) retention modes in a single nanoHPLC setup.
• Consecutive sample analysis: first RPLC, then PGC for non-retained compounds.
• Online coupling with mass spectrometric detection for both separation modes.

Main Results:

• Successful analysis of protein, peptide, and oligosaccharide mixtures within the same setup.
• Demonstrated ability to capture hydrophilic compounds not accessible by RPLC alone.
• Extended the accessible analytical range beyond conventional RPLC capabilities for low femtomole samples.

Conclusions:

• The dual gradient RPLC-PGC system significantly enhances the scope of proteomic and glycoproteomic analyses.
• This approach effectively addresses the limitations of RPLC for hydrophilic and short peptide analytes.
• Offers a more comprehensive analytical solution for complex biological samples.