Structural surfaceomics of Nomo-1 using PhoX cross-linker with timsTOF

The project aimed to profile the cell surface proteins of Nomo-1 (AML cell line) using structural surfaceomics for identification of protein conformation-based cancer antigens thereby expanding the toolkit for cancer target discovery for immunotherapeutic targeting. To achieve the goal, cell surface capture (CSC) was integrated with cross-linking mass spectrometry (XL-MS). PhoX was used as a cross-linker to freeze the structural conformations of protein in three-dimensional space, followed by biotinylation of cell surface proteins to enable enrichment of cell surface proteins to allow focused XL-MS analysis of those enriched proteins. PhoX having in-built phosphonate-based IMAC handle which allowed additional enrichment of cross-linked peptides.