NR ANNZ
AU Torrent,J.; Alvarez-Martinez,M.T.; Heitz,F.; Liautard,J.P.; Balny,C.; Lange,R.
TI Alternative prion structural changes revealed by high pressure
QU Biochemistry 2003 Feb 11; 42(5): 1318-25
PT journal article
AB At high temperature, recombinant hamster prion protein (SHaPrP(90)(-)(231)) undergoes aggregation and changes from a predominantly alpha-helical to beta-sheet conformation. We then applied high pressure (200 MPa) to the beta-sheet-rich conformation. The aggregation was reversed, and the original tertiary and secondary structures were recovered at ambient pressure, after pressure release. The application of a pressure of 200 MPa thus allowed studying the heat-induced equilibrium refolding in the absence of protein aggregation. Prion protein unfolding as a function of high pressure was also investigated. Simple two-state, reversible unfolding transitions were observed, as monitored by spectral changes in the UV and fluorescence of the hydrophobic probe 8-anilino-1-naphthalene sulfonate. However, these heat- and pressure-induced conformers differed in their unfolding free energy. At pressures over 400 MPa, strong thioflavin-T binding was observed, suggesting a further structural change to a metastable oligomeric structure.
AD INSERM U128, 1919 Route de Mende, F-34293 Montpellier cedex 5, France, INSERM U431, IFR 56, Place Eugene Bataillon, F-34095 Montpellier Cedex 5, France, and CRBM, CNRS-UPR 1086, IFR24, 1919 Route de Mende, F-34293 Montpellier Cedex 5, France.
SP englisch
PO USA