Simultaneous detection of tyrosine and structure-specific intrinsic fluorescence in the fibrillation of Alzheimer's associated peptides.

Simultaneous detection of tyrosine and structure-specific intrinsic fluorescence in the fibrillation of Alzheimer's associated peptides. Chemphyschem. 2020 Oct 02;: Authors: Singh A, Khatun S, Gupta AN Abstract Understanding of the structural changes during their aggregation and interaction is a prerequisite for establishing the precise clinical relevance of human islet amyloid polypeptide (hIAPP) (involved in Type-II Diabetes Mellitus) in the treatment of Alzheimer's disease stemmed from beta-amyloid (Aβ). Herein, we show that the steady-state emission spectra obtained from photoluminescence (PL) simultaneously capture both the tyrosine derivative (tyrosinate) and the structure-specific intrinsic fluorescence during the aggregation of Aβ and hIAPP. We observe multiple peaks in the emission spectra which exist for structure-specific intrinsic fluorescence and use the second derivative UV-Vis spectra and the shift in the tyrosine peak as a quantitative measure of the dissimilitude in the electronic states and the fibril growth. We further applied these techniques to detect the static electric field (0, 40, 120, 200 V/cm) induced promotion and inhibition of fibrillation in Aβ, hIAPP and their electric field dependent role in the fibrillation of Aβ:hIAPP(1:1). The results were corroborated by field-emission scanning electron microscopy (FESEM), and the determinations of secondary structures by Fourier transform infrared spectroscopy...
Source: Chemphyschem - Category: Chemistry Authors: Tags: Chemphyschem Source Type: research