Optimization of methods for the quantitative analysis of global cell surface proteome and cell surface polarization

The application of our cell surface labeling and peptide enrichment workflow to MDCKII epithelial monolayers enabled large-scale quantification of apical versus basolateral domains, yielding over 2,100 proteins with 235 showing significant polarized distribution in agreement with known biology. This method offers high specificity for extracellular labeling and quantitative resolution of cell surface protein polarization, providing a powerful platform for studying epithelial biology and identifying extracellular epitopes relevant to diagnostics and therapeutic targeting.