Mass-spectrometry proteomics data
Cross-linking/mass spectrometry has become an important approach for studying protein structures and protein-protein interactions. The amino acid composition of some protein regions impedes the detection of cross-linked residues, although it would yield invaluable information for protein modelling. Here, we report on a sequential digestion strategy with trypsin and elastase to penetrate regions with a low density of trypsin cleavage sites. We exploited intrinsic substrate recognition properties of elastase to specifically target larger tryptic peptides. Our application of this protocol to the TAF4-12 complex allowed us to identify cross-links in previously inaccessible regions.
Dau E, Gupta K, Berger I, Rappsilber J (2019) Sequential digestion with Trypsin and Elastase in cross-linking mass spectrometry. Analytical Chemistry. https://doi.org/10.1021/acs.analchem.8b05222