title: The multiplicity of post-translational modifications in pro-opiomelanocortin-derived peptides.
abstract: The precursor protein, pro-opiomelanocortin (POMC) undergoes extensive post-translational processing in a tissue-specific manner to yield various biologically active peptides involved in diverse cellular functions. The recently developed method of matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) for direct tissue analysis has proved to be a powerful tool for investigating the distribution of peptides and proteins. In particular, topological mass spectrometry analysis using MALDI-MS can selectively provide a mass profile of the hormones included in cell secretory granules. An advantage of this technology is that it is possible to analyze a frozen thin slice section, avoiding an extraction procedure. Subsequently, tandem mass spectrometry (MS/MS) has a profound impact on addressing the modified residues in the hormone molecules. Based on these strategies with mass spectrometry, several interesting molecular forms of POMC-derived peptides have been found in the fish pituitary, such as novel sites of acetylation in α-melanocyte-stimulating hormone (MSH), hydroxylation of a proline residue in β-MSH, and the phosphorylated form of corticotropin-like intermediate lobe peptide.
authors.affiliation: Health Research Institute, National Institute of Advanced Industrial Science and Technology (AIST) , Ikeda , Japan.
authors.forename: Akikazu
authors.initials: A
authors.lastname: Yasuda
authors.affiliation: Department of Biology, Appalachian State University , Boone, NC , USA.
authors.forename: Leslie Sargent
authors.initials: LS
authors.lastname: Jones
authors.affiliation: Health Research Institute, National Institute of Advanced Industrial Science and Technology (AIST) , Ikeda , Japan.
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Shigeri
keywords: CLIP; END; MALDI-MS; MSH; POMC; post-translational modification; topological mass spectrometry analysis