NR ATSI
AU Cordeiro,Y.; Kraineva,J.; Gomes,M.P.B.; Lopes,M.H.; Martins,V.R.; Lima,L.M.T.R.; Foguel,D.; Winter,R.; Silva,J.L.
TI The amino-terminal PrP domain is crucial to modulate prion misfolding and aggregation
QU Biophysical Journal 2005 Oct; 89(4): 2667-76
PT journal article
AB The main hypothesis for prion diseases is that the cellular protein (PrPc) can be altered into a misfolded, beta-sheet-rich isoform (PrPsc), which undergoes aggregation and triggers the onset of transmissible spongiform encephalopathies. Here, we investigate the effects of amino-terminal deletion mutations, rPrP(Delta51-90) and rPrP(Delta32-121), on the stability and the packing properties of recombinant murine PrP. The region lacking in rPrP(Delta51-90) is involved physiologically in copper binding and the other construct lacks more amino-terminal residues (from 32 to 121). The pressure stability is dramatically reduced with decreasing N-domain length and the process is not reversible for rPrP(Delta51-90) and rPrP(Delta32-121), whereas it is completely reversible for the wild-type form. Decompression to atmospheric pressure triggers immediate aggregation for the mutants in contrast to a slow aggregation process for the wild-type, as observed by Fourier-transform infrared spectroscopy. The temperature-induced transition leads to aggregation of all rPrPs, but the unfolding temperature is lower for the rPrP amino-terminal deletion mutants. The higher susceptibility to pressure of the amino-terminal deletion mutants can be explained by a change in hydration and cavity distribution. Taken together, our results show that the amino-terminal region has a pivotal role on the development of prion misfolding and aggregation.
MH Amino Acid Substitution; Animals; Binding Sites; Dimerization; Mice; Multiprotein Complexes/analysis/chemistry; Mutagenesis, Site-Directed; Prions/*analysis/*chemistry/genetics; Protein Binding; Protein Conformation; Protein Denaturation; Protein Folding; Protein Structure, Tertiary; Recombinant Proteins/analysis/chemistry; Research Support, Non-U.S. Gov't; Structure-Activity Relationship
AD Instituto de Bioquimica Medica, Centro Nacional de Ressonancia Magnetica Nuclear de Macromoleculas Jiri Jonas, Universidade Federal do Rio de Janeiro, Brazil.
SP englisch
PO USA