Detectability of Biotin Tags by LC–MS/MS

The high affinity of biotin to streptavidin has made it one the most widely used tags in proteomics. Early methods for enrichment alone and mostly ignored biotin-labeled peptide. Recent advances labeling have led an increase biotinylation efficiency shifted interest detection site biotinylation. This increased confidence identification provided additional structural information, yet requires efficient release biotinylated protein/peptide sensitive separation peptides by LC-MS/MS. Despite its long use proteomics, effect on chromatographic, ionization, fragmentation behavior ultimate is not well understood. To address this, we compare two commercially available labels, EZ-Link Sulfo-NHS-Biotin Sulfo-NHS-SS-Biotin, latter containing a labile linker efficiently determine effects peptide modification detection. We describe hydrophobicity charge reduction with increasing number labels attached. On basis our data, recommend gradient optimization account more hydrophobic include singly charged precursors biotin.