NR ATAQ
AU Diaz-Avalos,R.; King,C.Y.; Wall,J.; Simon,M.; Caspar,D.L.
TI Strain-specific morphologies of yeast prion amyloid fibrils
QU Proceedings of the National Academy of Sciences of the United States of America 2005 Jul 19; 102(29): 10165-70
IA http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=1177419
PT journal article
AB Mass per length (mpl) measurements on single amyloid fibrils that specifically propagate the [VH], [VK], and [VL] strains of the yeast prion [PSI] reveal unanticipated differences in their structures. Many fibrils have approximately 1.0 prion molecule per 4.7-A cross-beta repeat period, which is consistent with a self-replicating model built by parallel beta-sheet hydrogen-bonding of like prion peptide segments, but other fibrils are definitely heavier. The predominantly straight fibrils of the dominant [VH] strain have a bimodal mpl distribution, corresponding to components with approximately 1.0 and 1.2 prions per repeat. Fibrils of the weaker [VK] strain, which are almost all wavy, have a monodisperse mpl distribution with a mean of 1.15 prions per repeat. The recessive [VL] strain sample has approximately 1.05 prions per repeat in single fibrils and includes approximately 10% double fibrils, which are rare in the duplicate [VH] and [VK] samples. All of these samples were assembled from purified recombinant Sup35 prion protein by seeded growth on nuclei extracted from yeast bearing the three [PSI] strains. Infectious and noninfectious spontaneously assembled fibrils of the recombinant prion protein also display different heterogeneous morphologies. The strain-specific morphological differences we have observed directly confirm the structural prediction of the protein-only prion theory but do not have an obvious molecular explanation.
MH Amyloid/metabolism/*ultrastructure; Comparative Study; Green Fluorescent Proteins; Microscopy, Electron; Prions/*metabolism; Research Support, N.I.H., Extramural; Research Support, U.S. Gov't, Non-P.H.S.; Research Support, U.S. Gov't, P.H.S.; Saccharomyces cerevisiae/*metabolism; Saccharomyces cerevisiae Proteins/*metabolism
AD Institute of Molecular Biophysics, Florida State University, Tallahassee, FL 32306-4380, USA. diaz@sb.fsu.edu
SP englisch
PO USA