Pituitary peptide profiles obtained using direct MALDI-TOF MS. Panels (a–c) show peptides detected in different mass regions. Known peptides are labeled based on mass match to the LC-MS sequencing data: a–AVP; b–γ-MSH; c–di-Ac-α-MSH (3–13); d–α-MSH; e–Ac-α-MSH; f–di-Ac-α-MSH; h–J-peptide; i–Ac-J-peptide; j–J-peptide + N-terminal Arg; k–CLIP (1–20); l–CLIP (1–21); m–CLIP, n–phosphorylated CLIP; o–Ac-β-endorphin (1–26); p–Ac-β-endorphin (1–27), q–ACTH (1–28); r–γ-LPH (10–38); s–γ-LPH. Abbreviations: proVP, provasopressin-neurophysin 2 copeptin; AVP, arginine vasopressin; ACTH, adrenocorticotropic hormone; MSH, melanocyte-stimulating hormone; Ac, acetylated; CLIP, corticotropin-like intermediate peptide; and LPH, lipotropin. Labeled m/z correspond to monoisotopic masses of protonated molecular ions.