PEPPI-MS: gel-based sample pre-fractionation for deep top-down and middle-down proteomics.

Area of Science:

• Proteomics
• Biochemistry
• Analytical Chemistry

Background:

• Top-down and middle-down proteomics require efficient proteoform detection from complex samples.
• Protein pre-fractionation is crucial for reducing sample complexity.
• Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) is a common protein separation technique, but efficient intact protein recovery from gels has been challenging.

Purpose of the Study:

• To develop a rapid and efficient method for extracting intact proteins from SDS-PAGE gels for top-down and middle-down proteomics.
• To overcome the limitations of conventional protein recovery methods from polyacrylamide gels.

Main Methods:

• Development and implementation of the passively eluting proteins from polyacrylamide gels as intact species for mass spectrometry (PEPPI-MS) protocol.
• Utilizing SDS-PAGE for initial protein separation.
• Passive elution of intact proteins from the gel matrix.

Main Results:

• PEPPI-MS enables efficient recovery of intact proteins (<100 kDa) separated by SDS-PAGE with a median efficiency of 68% within 10 minutes.
• The method requires no specialized equipment, making it economical.
• The entire protocol, from electrophoresis to purification, can be completed in under 5 hours.
• PEPPI fractions can be combined with other separation techniques for multidimensional proteome analysis.

Conclusions:

• PEPPI-MS provides a rapid, efficient, and economical solution for intact protein extraction from SDS-PAGE gels.
• This method facilitates improved proteoform analysis in top-down and middle-down proteomics.
• The protocol integrates seamlessly with other separation techniques for comprehensive proteome studies.