Cysteine-enabled Cleavability to Advance Cross-linking Mass Spectrometry for Global Analysis of Endogenous Protein-Protein Interactions

We have employed the sulfoxide-based cleavability to establish a novel cysteine-based MS-cleavable XL-MS platform, enabling proteome-wide PPI analysis using non-cleavable heterobifunctional K-C linkers. The effectiveness of the newly established platform has been demonstrated using three commercially available and non-cleavable NHS ester-haloacetamide heterobifunctional cross-linkers to map in vivo PPIs from HEK 293 cells.