NR AUAJ
AU Goncharov,V.A.
TI Mass spectroscopic analysis of Sup35NM prion polymerization
QU Biophysical Journal 2005 Dec; 89(6): 4139-48
PT journal article
AB Sup35NM, the prion determining domain of the protein responsible for the yeast prion phenomenon [Psi], has become a powerful model for studying key processes in amyloid-related human diseases. One of these processes is a conformational conversion of soluble precursor protein into insoluble fibrillar structures. In this study, we created a set of Sup35NM mutants and used proteolytic digestion coupled with mass spectroscopy to monitor local structure of the protein during polymerization. Experimental data were compared to a network model and showed that during the conformational conversion residue Arg-28 became highly protected from cleavage, residue Arg-98 remained partially solvent exposed, and residues between 28 and 98 showed an intermediate degree of protection. In addition, we found that a distinct subset of proteolytic polypeptides spanning 28-98 residues segment spontaneously formed stable dimers. This finding suggests that the [29-98] region is the key interacting region of Sup35NM responsible for amyloid conversion.
MH Amyloid/analysis/*chemistry/*ultrastructure; Binding Sites; Computer Simulation; Dimerization; *Models, Chemical; *Models, Molecular; Multiprotein Complexes/analysis/chemistry/ultrastructure; Polymers/chemistry; Prions/analysis/*chemistry/*ultrastructure; Protein Binding; Protein Conformation; Research Support, Non-U.S. Gov't; Saccharomyces cerevisiae Proteins/analysis/*chemistry/*ultrastructure; Spectrum Analysis, Mass/*methods
AD Whitehead Institute for Biomedical Research, Cambridge, Massachusetts 02142, USA. goncharov@wi.mit.edu
SP englisch
PO USA