NR ALUT
AU Turk,E.; Teplow,D.B.; Hood,L.E.; Prusiner,S.B.
TI Purification and properties of the cellular and scrapie hamster prion proteins
QU European Journal of Biochemistry 1988 Sep 1; 176(1): 21-30
PT journal article
AB During scrapie infection an abnormal isoform of the prion protein (PrP), designated PrPsc, accumulates and is found to copurify with infectivity; to date, no nucleic acid has been found which is scrapie-specific. Both uninfected and scrapie-infected cells synthesize a PrP isoform, denoted PrPc, which exhibits physical properties that differentiate it from PrPsc. PrPc was purified by immunoaffinity chromatography using a PrP-specific monoclonal antibody cross-linked to protein-A-Avidgel. PrPsc was purified by detergent extraction, poly(ethylene glycol) precipitation and repeated differential centrifugation of PrPsc polymers. Both PrP isoforms were found to have the same N-terminal amino acid sequence which begins at a predicted signal peptide cleavage site. The first 8 residues of PrPc were found to be KKXPKPGG and the first 29 residues of PrPsc were found to be KKXPKPGGWNTGGSXYPGQGSPGGNRYPP. Arg residues 3 and 15 in PrPsc and 3 in PrPc appear to be modified since no detectable signals (denoted X) were found at these positions during gas-phase sequencing. Both PrP isoforms were found to contain an intramolecular disulfide bond, linking Cys 179 and 214, which creates a loop of 36 amino acids containing the two N-linked glycosylation sites. Development of a purification protocol for PrPc should facilitate comparisons of the two PrP isoforms and lead to an understanding of how PrPsc is synthesized either from PrPc or a precursor.
IN Die Autoren stellten durch das Ansequenzieren von normalem und aus Prionen isoliertem Prionprotein fest, das beide mit der vorhergesagten Sequenz nach dem Signalpeptid beginnen. Die Anfangssquenzen waren KKXPKPGG beim PrPc und KKXPKPGGWNTGGSXYPGQGSPGGNRYPP beim PrPsc. Die Arginine 3 und 15 scheinen modifiziert zu sein, da sie in der Gasphasensequenzierung keine Signale lieferten. Beide Formen besaßen eine Disulphidbrücke zwischen den Cysteinen 179 und 214.
MH Amino Acid Sequence; Animal; Brain Chemistry; Cross Reactions; Disulfides/analysis; Electrophoresis, Polyacrylamide Gel; Hamsters; Immunologic Techniques; Mesocricetus; Prions/*analysis; Protein Processing, Post-Translational; Scrapie/*metabolism; Support, Non-U.S. Gov't; Support, U.S. Gov't, P.H.S.; Transcription, Genetic; Viral Proteins/genetics/*isolation & purification
AD Department of Neurology, School of Medicine, University of California, San Francisco 94143-0518.
SP englisch
PO Westdeutschland