title: Comparative two-dimensional mapping of prion protein isoforms in human cerebrospinal fluid and central nervous system.
abstract: The cellular prion protein (PrP(C)) is a glycosylphosphatidylinositol (GPI)-anchored glycoprotein abundant in neurons. Although its precise function is unknown, PrP(C) represents the substrate for the generation of a conformational pathogenic isoform (PrP(Sc)) in human and animal transmissible spongiform encephalopathies, or prion diseases. By applying novel solubilization cocktails, we analyzed normal human brain and cerebrospinal fluid (CSF) PrP(C) by immunoblot of two-dimensional (2-D) gel electrophoresis preparations, using specific antibodies. Here, we show that PrP(C) from brain and CSF is composed of several charge isomers of differently glycosylated isoforms of the full-length PrP(C) and two N-terminally truncated fragments of 20 and 18 kDa. In the CSF, substantial amounts of the highly glycosylated PrP(C) isoforms and of the unglycosylated 18 kDa fragment are detected. Our study, for the first time, provides a detailed 2-D map of human PrP(C) both in brain and CSF, and establishes an innovative and sensitive method that might help in detecting the CSF pathological PrP(Sc) isoform in vivo. It also shows the incredible microheterogeneity of such isoforms (ca. 60 spots!), as revealed in 2-D mapping, as opposed to 3-4 main zones by mono-dimensional sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE).
authors.affiliation: Department of Agricultural and Industrial Biotechnologies, University of Verona, Italy.
authors.forename: Annalisa
authors.initials: A
authors.lastname: Castagna
authors.forename: Natascia
authors.initials: N
authors.lastname: Campostrini
authors.forename: Alessia
authors.initials: A
authors.lastname: Farinazzo
authors.forename: Gianluigi
authors.initials: G
authors.lastname: Zanusso
authors.forename: Salvatore
authors.initials: S
authors.lastname: Monaco
authors.forename: Pier Giorgio
authors.initials: PG
authors.lastname: Righetti
mesh_terms: D001923:Brain Chemistry; D007562:Creutzfeldt-Jakob Syndrome / Q000134:cerebrospinal fluid; D015180:Electrophoresis, Gel, Two-Dimensional / Q000379:methods; D006801:Humans; D010449:Peptide Mapping / Q000379:methods; D018621:PrPC Proteins / Q000032:analysis*; D018620:PrPSc Proteins / Q000032:analysis* / Q000134:cerebrospinal fluid; D020033:Protein Isoforms / Q000032:analysis
chemical_list: D018621:PrPC Proteins; D018620:PrPSc Proteins; D020033:Protein Isoforms