title: Proteomics of bovine myelin sheath: characterization of a truncated form of P0 by MALDI-TOF/TOF mass spectrometry.
abstract: The glycoprotein P0, the major structural protein of the peripheral nerve myelin, plays a critical role in holding myelin lamellae together via interaction of both extracellular and cytoplasmic domains. Mutations in the human P0 gene give rise to severe and progressive forms of dominantly inherited peripheral neuropathies like CMT1B. Here we report on the characterization of a bovine P0-derived protein of nearly 26 kD that corresponds to the P0 protein truncated in its cytoplasmic domain. Matrix assisted laser desorption ionization (MALDI)-time-of-flight/time-of-flight (TOF/TOF) mass spectrometry (MS) analysis on its tryptic digest has provided a peptide mapping, the main difference of which from the normal P0 analog was represented by the absence of the cluster of peaks at m/z 1513.7501, 1530.7701, and 1546.7651. The latter corresponds to the P0 fragment QTPVLYAMLDHSR and to its pyroglutamic and methionine-oxidized derivatives. The species at 1530.7701 covering the sequence 186-198 of P0 is not an artifact and might have a functional role in the myelin architecture.
authors.affiliation: Institute of Neurological Sciences, Mangone (CS), Italy.
authors.forename: Antonio
authors.initials: A
authors.lastname: Qualtieri
authors.forename: Elena
authors.initials: E
authors.lastname: Urso
authors.forename: Maria
authors.initials: M
authors.lastname: Le Pera
authors.forename: Massimo
authors.initials: M
authors.lastname: Scornaienchi
authors.forename: Aldo
authors.initials: A
authors.lastname: Quattrone
authors.forename: Leonardo
authors.initials: L
authors.lastname: Di Donna
authors.forename: Anna
authors.initials: A
authors.lastname: Napoli
authors.forename: Giovanni
authors.initials: G
authors.lastname: Sindona
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002417:Cattle; D004586:Electrophoresis; D006868:Hydrolysis; D008969:Molecular Sequence Data; D018993:Myelin P0 Protein / Q000737:chemistry* / Q000302:isolation & purification; D009186:Myelin Sheath / Q000737:chemistry*; D011487:Protein Conformation; D040901:Proteomics; D012584:Sciatic Nerve / Q000737:chemistry; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D014357:Trypsin / Q000737:chemistry
chemical_list: D018993:Myelin P0 Protein; D014357:Trypsin