We describe here the first example of global chemoproteomic screening and substrate validation for HYPE mediated AMPylation in mammalian cell lysate. Through quantitative mass spectrometry-based proteomics coupled with novel chemoproteomic tools providing MS/MS evidence of AMP modification we identified a total of 27 AMPylated proteins, including the previously validated substrate, ER chaperone BiP (HSPA5), along with novel substrates involved in pathways of gene expression, ATP biosynthesis and maintenance of cytoskeleton. This dataset represents the largest library of AMPylated human proteins reported to date and a foundation for substrate-specific investigations that can ultimately decipher the complex biological networks involved in eukaryotic AMPylation.