NR AVAO
AU Corsaro,A.; Paludi,D.; Villa,V.; D'Arrigo,C.; Chiovitti,K.; Thellung,S.; Russo,C.; Di Cola,D.; Ballerini,P.; Patrone,E.; Schettini,G.; Aceto,A.; Florio,T.
TI Conformation dependent pro-apoptotic activity of the recombinant human prion protein fragment 90-231
QU International Journal of Immunopathology and Pharmacology 2006 Apr-Jun; 19(2): 339-56
PT journal article
AB The transition of prion protein from a mainly alpha-structured isoform (PrPc) to a beta sheet-containing protein (PrPsc) represents a major pathogenetic mechanism in prion diseases. To study the role of PrP structural conformation in prion-dependent neurodegeneration, we analysed the neurotoxicity of PrP in alpha and beta conformations, using a recombinant protein encompassing amino acids 90-231 of the human PrP (hPrP90-231). Using controlled thermal denaturation (53 degrees C, 1h) we converted hPrP90-231 in a structural isoform displaying PrPsc-related characteristics: high beta sheet content, increased aggregability and a slight increase in the resistance to protease K. In virtue of these structural changes, hPrP90-231 powerfully affected the survival of SH-SY5Y cells, inducing a caspase-3 and p38- dependent apoptosis. Conversely, in the native alpha-helix-rich conformation, hPrP90-231 did not show significant cell toxicity. The relationship between the structural state of hPrP90-231 and its neurotoxicity was demonstrated, inducing the thermal denaturation of the peptide in the presence of Congo red that prevented both the transition of hPrP90-231 into a beta-rich isoform and the acquisition of toxic properties. In conclusion, we report that the toxicity of hPrP90-231 is dependent on its three-dimensional structure, as is supposed to occur for the pathogen PrP during TSE.
MH Amyloid/biosynthesis; Apoptosis/*drug effects; Caspases/metabolism; Cell Line, Tumor; Cell Survival/drug effects; Circular Dichroism; Endopeptidase K/chemistry; Fluorescent Dyes; Humans; Hydrolysis; Immunoblotting; L-Lactate Dehydrogenase/metabolism; Microscopy, Electron; Necrosis; PrPc Proteins/*chemistry/*pharmacology; Protein Conformation; Protein Denaturation; Protein Structure, Secondary; Recombinant Proteins/chemistry/pharmacology; Research Support, Non-U.S. Gov't; Structure-Activity Relationship; Tetrazolium Salts; Thiazoles/metabolism; p38 Mitogen-Activated Protein Kinases/metabolism
AD Section of Pharmacology, Dept. Oncology Biology and Genetics, University of Genoa, Viale Benedetto XV 2, 16132 Genoa, Italy.
SP englisch
PO Italien