Program

Poster Presentations

Day 2, June 11（Thu.）　　Room P (5F 501+502)

2P-25

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Establishment of a plasma peptidomic analysis method using DIA-MS for the detection of organ-derived peptides

(¹Kitasato Univ., ²Kazusa DNA Res. Inst., ³Kitasato Univ., ⁴Kitasato Univ.)
^oYusei Okuda^1,2, Ryo Konno², Tomomi Taguchi³, Makoto Itakura^3,4, Ami Tamari¹, Takashi Matsui^1,4, Takeshi Miyatsuka³, Osamu Ohara², Yusuke Kawashima^1,2, Yoshio Kodera^1,4

Blood contains bioactive peptides (hormones and neuropeptides) that play key roles in homeostasis and disease responses. Well-known examples such as insulin, endorphins, and oxytocin regulate metabolism, pain, and stress and are used as biomarkers and peptide therapeutics. Therefore, detecting bioactive peptides in blood is critically important. Using a high-efficiency peptide extraction method (DS method [1]), followed by HPLC fractionation and ~200 DDA-MS runs, we previously detected >10,000 endogenous (native) plasma peptides, including 22 known bioactive peptides, and identified five novel bioactive peptides. In contrast, non-fractionated single-shot DDA-MS is dominated by peptides from high-abundance proteins such as albumin and immunoglobulins, making bioactive peptides harder to detect. DIA-MS provides high sensitivity and reproducibility. However, native peptidomics involves diverse cleavage patterns and a vast search space, making sequence-only predicted spectral libraries impractical. Furthermore, DDA libraries built only from the same sample may not fully leverage DIA sensitivity. Here, we constructed an empirical spectral library from DDA data of plasma and eleven organs and applied it to plasma DIA data [2], enabling detection of more native peptides, including low-abundance, organ-derived peptides. This workflow may also support inference of peptide tissue of origin, facilitating discovery of novel bioactive peptides and mechanistic studies of various diseases.

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