Evaluation of NHS-Acetate and DEPC labelling for determination of solvent accessible amino acid residues in protein complexes

The structural analysis of proteins and protein complexes is key for understanding their function and regulation. In order to gain structural information, we examined protein surface labelling using NHS-Acetate and DEPC following an MS-based workflow. Using two model proteins we characterise the obtained mass spectra and explore the applicability of a quantitative approach for determining of solvent accessible amino acid residues on the surface of proteins and protein complexes. The modified peptides were analysed by LC-MS/MS and processed using MaxQuant for identification and intensity determination of labelled and unlabelled peptides.