Extended Data Fig. 7. LC-MS/MS analysis of the processed NT peptide.

a. The mass spectrum of the triply charged NT (NT³⁺) peptide eluted at 18.96 min in conditioned medium of S2 cells expressing full-length human NT precursor. The labeled three peaks are the isotopic envelope of NT³⁺ with a mass accuracy less than 2 ppm from the theoretical m/z value of 585.31050. b. The tandem mass spectrum of the triply charged NT³⁺ peptide. The m/z values of major fragment ions are designated, confirming the peptide as biologically active 13-amino acid NT. c. The amount of NT in S2 medium and fly GI tracts from adult Gr36C-NT flies (350 guts collected for each genotype) was quantified (N.D., not detected).