Detecting beta-amyloid aggregation from time-resolved emission spectra.
Methods Appl Fluoresc
; 6(2): 024002, 2018 Jan 22.
Article
in En
| MEDLINE
| ID: mdl-29210673
ABSTRACT
The aggregation of beta-amyloids is one of the key processes responsible for the development of Alzheimer's disease. Early molecular-level detection of beta-amyloid oligomers may help in early diagnosis and in the development of new intervention therapies. Our previous studies on the changes in beta-amyloid's single tyrosine intrinsic fluorescence response during aggregation demonstrated a four-exponential fluorescence intensity decay, and the ratio of the pre-exponential factors indicated the extent of the aggregation in the early stages of the process before the beta-sheets were formed. Here we present a complementary approach based on the time-resolved emission spectra (TRES) of amyloid's tyrosine excited at 279 nm and fluorescence in the window 240-450 nm. TRES have been used to demonstrate sturctural changes occuring on the nanosecond time scale after excitation which has significant advantages over using steady-state spectra. We demonstrate this by resolving the fluorescent species and revealing that beta-amyloid's monomers show very fast dielectric relaxation, and its oligomers display a substantial spectral shift due to dielectric relaxation, which gradually decreases when the oligomers become larger.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Spectrometry, Fluorescence
/
Amyloid
Type of study:
Screening_studies
Limits:
Humans
Language:
En
Journal:
Methods Appl Fluoresc
Year:
2018
Document type:
Article
Affiliation country:
United kingdom