Polymerization of proteins into amyloid protofibrils shares common critical oligomeric states but differs in the mechanisms of their formation.

Amyloid protofibril formation of phosphoglycerate kinase (PGK) and Syrian hamster prion protein (SHaPrP(90-232)) were investigated by static and dynamic light scattering, size exclusion chromatography and electron microscopy. Changes in secondary structure were monitored by Fourier transform infrared spectroscopy and by circular dichroism. Protofibril formation of the two proteins is found to be a two-stage process.

Formation of critical oligomers is a key event during conformational transition of recombinant syrian hamster prion protein.

We have investigated the conformational transition and aggregation process of recombinant Syrian hamster prion protein (SHaPrP90-232) by Fourier transform infrared spectroscopy, circular dichroism spectroscopy, light scattering, and electron microscopy under equilibrium and kinetic conditions. SHaPrP90-232 showed an infrared absorbance spectrum typical of proteins with a predominant alpha-helical structure both at pH 7.0 and at pH 4.