Erlangen 2018 – wissenschaftliches Programm
MO 2.2: Vortrag
Montag, 5. März 2018, 10:45–11:00, PA 1.150
In-Depth Investigation of the Aggregation Process of Insulin with Time-Resolved Fluorescence Studies — •Bastian Geissler, Dirk Wesberg, and Patrick Nuernberger — Physikalische Chemie II, Ruhr-Universität Bochum, 44780 Bochum
The quaternary structure of proteins can be essential for a certain functionality. On the contrary, misfolded proteins can cause cellular dysfunction and are suspected to determine degenerative diseases like Parkinson’s or Alzheimer’s disease. Misfolded proteins autocatalytically form insoluble amyloid fibrils, which are commonly known as plaques. The formation of fibrils can be observed with marker dyes like Thioflavin T (ThT) whose fluorescence yield increases during the process due to the modified surrounding. In this study, we employ ThT and measure the aggregation of insulin fibrils using time-resolved fluorescence, either by time-correlated single-photon counting or by a streak camera, and with pulsed excitation alternately at 375 or 405 nm in order to excite different sub-ensembles of the ThT molecules. Whereas the process itself takes hours, we monitor not only the fluorescence yield but also how the lifetimes and emission spectra of ThT change during fibril formation. Since the latter two aspects are associated with the geometry of ThT, we obtain insight into the binding situation of ThT to the fibrils and during the fibril formation.