Endogenous peptide discovery of the rat circadian clock: A focused study of the suprachiasmatic nucleus by ultrahigh performance tandem mass spectrometry

Ji Eun Lee, Norman Atkins, Nathan G. Hatcher, Leonid Zamdborg, Martha U. Gillette, Jonathan V. Sweedler, Neil L. Kelleher

Research output: Contribution to journalArticle


Understanding how a small brain region, the suprachiasmatic nucleus (SCN), can synchronize the body's circadian rhythms is an ongoing research area. This important time-keeping system requires a complex suite of peptide hormones and transmitters that remain incompletely characterized. Here, capillary liquid chromatography and FTMS have been coupled with tailored software for the analysis of endogenous peptides present in the SCN of the rat brain. After ex vivo processing of brain slices, peptide extraction, identification, and characterization from tandem FTMS data with <5-ppm mass accuracy produced a hyperconfident list of 102 endogenous peptides, including 33 previously unidentified peptides, and 12 peptides that were post-translationally modified with amidation, phosphorylation, pyroglutamylation, or acetylation. This characterization of endogenous peptides from the SCN will aid in understanding the molecular mechanisms that mediate rhythmic behaviors in mammals.

Original languageEnglish (US)
Pages (from-to)285-297
Number of pages13
JournalMolecular and Cellular Proteomics
Issue number2
StatePublished - Feb 1 2010


ASJC Scopus subject areas

  • Analytical Chemistry
  • Biochemistry
  • Molecular Biology

Cite this