PROTEOME-SCALE RECOMBINANT STANDARDS AND A ROBUST HIGH-SPEED SEARCH ENGINE TO ADVANCE CROSS-LINKING MS-BASED INTERACTOMICS

Abstract

AO_SCPLOWBSTRACTC_SCPLOWAdvancing data analysis tools for proteome-wide cross-linking mass spectrometry (XL-MS) requires ground-truth standards that mimic biological complexity. Here, we develop wellcontrolled XL-MS standards comprising hundreds of recombinant proteins that are systematically mixed for cross-linking. We use one standard dataset to guide the development of Scout, a search engine for XL-MS with MS-cleavable cross-linkers. Using other, independent datasets from our standards as well as published datasets, we benchmark the performance of Scout and existing XL-MS software. This demonstrates that Scout offers the best combination of speed, sensitivity, and false-discovery rate control. These results illustrate how our large recombinant standards can support the development of XL-MS analysis tools and evaluation of XL-MS results.