A facile and dynamic assay for the detection of peptide aggregation.

We report on a facile method to detect the aggregation and co-aggregation of peptides by tryptophan fluorescence spectroscopy. Peptide aggregates (PAs) play a pivotal role in neurodegenerative diseases, such as Alzheimer's and Parkinson's. The detection of the formation of aggregates, especially in the early stage, will facilitate the diagnosis and treatment of the associated disease. In this study, by choosing a tryptophan-containing peptide of EP2, we investigated its fluorescence spectroscopic characteristics in the process of PAs. The results showed that the intensity of emission spectra was significantly enhanced with the formation of PAs within 48 h. In addition, by employing EP2 as a fluorescence probe, we found that EP2 was able to effectively monitor the aggregation of other peptides/proteins that are otherwise difficult to detect with conventional approach. Thus, these preliminary data provide a promising diagnostic tool to detect the formation of PAs.