NR AWFS
AU Gobbi,M.; Rigamonti,V.; Ceci,P.; Manzoni,C.; Colombo,L.; Tagliavini,F.; Forloni,G.; Salmona,M.
TI Studies on the polymerization reactions of Gerstmann-Sträussler-Scheinker disease prion peptide using surface plasmon resonance
QU International Conference - Prion 2006: Strategies, advances and trends towards protection of society - 3.10.-6.10.2006, Torino, Italy, Lingotto Conference Centre - Poster sessions S-10
PT Konferenz-Poster
AB The polymerization of amyloidogenic peptides resembles a nucleation-growth process, with an initial lag phase followed by a rapid assembly. The lag phase is the rate-limiting step, possibly associated to changes in the protein folding and leading to soluble oligomers with b-sheet structure. These structures form the nuclei that catalyze a templated assembly, in which a thermodynamically favorable association of peptide onto the ends of the growing (proto)fibrils leads to a fast elongation. Different approaches permit to follow the time-course of these polymerization phases on a scale of hours-days. However, the characterization of the underlying binding events requires information on both association and dissociation rates, with collection of data on a much shorter time-scale. Recent studies showed that surface plasmon resonance (SPR)-based technology, which monitor molecular interactions in real time (secs), might well serve to this purpose. We have used SPR to study the polymerization of PrP82-146, an amylodogenic prion peptide found in the brains of patients afflicted with Gerstmann-Sträussler-Scheinker disease (GSS), a familial prion disease. Short-term flow of low-order oligomers onto prefibrillar PrP82-146 aggregates (immobilized on the sensor chip) resulted in the significant growth of the latter, with the characteristics of an elongation process. Analysis of association-dissociation curves allowed to suggest a "dock-and-lock" model, in which the "locking" step is due to sequential isomerization steps, each increasing the affinity until a condition of irreversible binding is reached. The corresponding kinetic constants were also determined. Ongoing SPR studies aim to characterize the binding events which occur: 1) in the different phases of the polymerization process or between species of different size; 2) in the presence of interfering compounds; 3) with PrP82-146 peptides from different animal species ("Heteroprion" project).
AD M. Gobbi, V. Rigamonti, P. Cecil, C. Manzoni, L. Colombo, G. Forloni, M. Samona: Istituto di Ricerche Farmacologiche "Mario Negri", 20157, Milano Italy; F. Tagliavini: Istituto Nazionale Neurologico "Carlo Besta", Milan, Italy. E-mail: Gobbi@marionegri.it
SP englisch
PO Italien