Optimized Biotinylated Peptide Detection Method for Characterizing the Cell Surface Proteome.

Area of Science:

• Proteomics
• Cell Biology
• Biochemistry

Background:

• Cell surface proteins (CSPs) are vital for cellular functions and cell type differentiation.
• Existing methods for CSP characterization are often low-throughput and provide limited data.
• Information on cell surface proteins is frequently fragmented across publications, hindering comprehensive analysis.

Purpose of the Study:

• To develop a high-throughput method for comprehensive cell surface proteome analysis.
• To overcome limitations of low-throughput techniques and scattered data.
• To enable detailed characterization of cell surface proteins and their functions.

Main Methods:

• Utilized biotinylation of accessible primary amino groups on extracellular regions of CSPs.
• Developed a high-throughput protocol to generate hundreds of CSP-specific peptides in one experiment.
• Applied the method to both soluble and adherent cells, including side-selective biotinylation of epithelial cells.

Main Results:

• Successfully generated numerous cell type-specific biotinylated peptides from cell surface proteins.
• The protocol is effective for analyzing both soluble and adherent cell surface proteins.
• Enabled qualitative and quantitative characterization of proteins in apical and basolateral membranes of epithelial cells.

Conclusions:

• The developed high-throughput method significantly advances cell surface protein identification and characterization.
• Identified CSP peptides serve as valuable targets for antibody development, drug discovery, and host-pathogen interaction studies.
• Label-free quantification provides insights into CSP abundance in different membrane regions, aiding functional studies.