NR APJA
AU Kundu,B.; Maiti,N.R.; Jones,E.M.; Surewicz,K.A.; Vanik,D.L.; Surewicz,W.K.
TI Nucleation-dependent conformational conversion of the Y145Stop variant of human prion protein: structural clues for prion propagation.
QU Proceedings of the National Academy of Sciences of the United States of America 2003 Oct 14; 100(21): 12069-74
PT journal article
AB One of the most intriguing disease-related mutations in human prion protein (PrP) is the Tyr to Stop codon substitution at position 145. This mutation results in a Gerstmann-Sträussler-Scheinker-like disease with extensive PrP amyloid deposits in the brain. Here, we provide evidence for a spontaneous conversion of the recombinant polypeptide corresponding to the Y145Stop variant (huPrP23-144) from a monomeric unordered state to a fibrillar form. This conversion is characterized by a protein concentration-dependent lag phase and has characteristics of a nucleation-dependent polymerization. Atomic force microscopy shows that huPrP23-144 fibrils are characterized by an apparent periodicity along the long axis, with an average period of 20 nm. Fourier-transform infrared spectra indicate that the conversion is associated with formation of beta-sheet structure. However, the infrared bands for huPrP23-144 are quite different from those for a synthetic peptide PrP106-126, suggesting conformational non-equivalence of beta-structures in the disease-associated Y145Stop variant and a frequently used short model peptide. To identify the region that is critical for the self-seeded assembly of huPrP23-144 amyloid, experiments were performed by using the recombinant polypeptides corresponding to prion protein fragments 23-114, 23-124, 23-134, 23-137, 23-139, and 23-141. Importantly, none of the fragments ending before residue 139 showed a propensity for conformational conversion to amyloid fibrils, indicating that residues within the 138-141 region are essential for this conversion.
MH Amino Acid Substitution; Codon, Terminator/genetics; Endopeptidase K; Gerstmann-Sträussler-Scheinker Disease/etiology/genetics/metabolism; Human; In Vitro; Microscopy, Atomic Force; Microscopy, Electron; Mutagenesis, Site-Directed; Peptide Fragments/chemistry; Peptide Mapping; Prions/*chemistry/*genetics/ultrastructure; Protein Conformation; Protein Structure, Secondary; Recombinant Proteins/chemistry/genetics/ultrastructure; Spectroscopy, Fourier Transform Infrared; Support, U.S. Gov't, P.H.S.; *Variation (Genetics)
AD Department of Physiology and Biophysics, Case Western Reserve University, 3109 Adelbert Road, Cleveland, OH 44106, USA
SP englisch
PO USA