HeLa cell protein interactome of polyamine affinity-based probes (probe-modified peptides)

HeLa cells were incubated with affinity-based probes designed as synthetic analogs of endogenous metabolites: putrescine, spermidine, and spermine. Probe-protein interactions were captured in situ using UV-induced crosslinking. After cell lysis, the probe–protein conjugates were subjected to bioorthogonal ligation with a biotinylation reagent, followed by tryptic digestion and affinity purification of the probe-labeled peptides, which were then analyzed by LC-MS/MS.