Reliable characterisation of the fibrillogenesis kinetics of amyloid proteins is of uppermost importance for instance to study the effect of inhibitor molecules of potential pharmacological importance or of familial disease-associated mutations [8]. Aggregation kinetics can be monitored by absorbance and scattering determinations [9] and [10], sedimentation assays, circular dichroism (CD) [11] and [12], dynamic and static light scattering [13], Congo Red binding [14], ThT binding [15] and [16],
A769662 microscopy (EM), atomic forces microscopy (AFM) [17] or Trp/Tyr anisotropy [18] and [19]. All of these instrumental techniques suffer some associated technical limitations. For instance, absorbance and scattering depend on the fibril morphology (in a non-obvious way) [20], CD only determines soluble species and amyloid fibrils usually undergo rapid precipitation, Congo Red is not a specific dye and it is a kinetic inhibitor molecule [21], the quantum yield of ThT fluorescence depends dramatically of amyloid fibril type and there is a number of amyloid fibrils with a very modest and unappreciable ThT fluorescence [4]. Obviously, Trp/Tyr anisotropy can only be applied to
peptides and proteins containing such residues.
