Cell surface protein biotinylation for SDS-PAGE analysis.

Cell surface proteins play a very important role in physiology and pathology and are receiving increased attention by the pharmaceutical industry as valuable targets for development of new therapeutics. However, owing to the very nature of this category of proteins, their comprehensive study remains an elusive task. A number of methods have been proposed to enrich and purify cell surface proteins. Among them, usage of biotinylating reagents and exploitation of the strong interaction between biotin and streptavidin for the purification of biotinylated proteins has rapidly gained in popularity and allowed some of the most significant progresses in quantitative proteomics. This chapter focuses on methods for cell surface biotinylation with commercially available reagents, capture by avidin-affinity chromatography and release of the biotinylated surface proteins for downstream analysis by electrophoretic techniques.