NR ANXB
AU Bosques,C.J.; Imperiali,B.
TI The interplay of glycosylation and disulfide formation influences fibrillization in a prion protein fragment
QU Proceedings of the National Academy of Sciences of the United States of America 2003 Jun 24; 100(13): 7593-8
PT journal article
AB It is now accepted that the structural transition from cellular prion protein (PrPc) to proteinase K-resistant prion protein scrapie (PrPsc) is the major event leading to transmissible spongiform encephalopathies. Although the mechanism of this transition remains elusive, glycosylation has been proposed to impede the PrPc to PrPsc conversion. To address the role of glycosylation, we have prepared glycosylated and unglycosylated peptides derived from the 175-195 fragment of the human prion protein. Comparison of the structure, aggregation kinetics, fibril formation capabilities, and redox susceptibility of Cys-179 has shown that the N-linked glycan (at Asn-181) significantly reduces the rate of fibrillization by promoting intermolecular disulfide formation via Cys-179. Further-more, the aggressive fibrillization of a C179S mutant of this fragment highlights the significant role of disulfide stability in retarding the rate of fibril formation. The implications of these studies are discussed in the context of fibril formation in the intact prion protein.
MH Amino Acid Sequence; Circular Dichroism; Congo Red/pharmacology; *Disulfides/chemistry; Dithiothreitol/pharmacology; *Glycosylation; Human; Kinetics; Magnetic Resonance Spectroscopy; Microscopy, Electron; Models, Biological; Molecular Sequence Data; Mutation; Oxidation-Reduction; Peptides/chemistry; Polysaccharides/chemistry; PrP 27-30 Protein/*chemistry/metabolism; Prions/*chemistry; Protein Binding; Spectroscopy, Fourier Transform Infrared; Spectrum Analysis, Mass; Support, U.S. Gov't, P.H.S.; Time Factors
AD Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139, USA
SP englisch
PO USA
EA pdf-Datei, und Figure 7, Figure 8, Tabelle 2 und Supporting Text