A novel fluorescent protein chromophore analogue to simultaneously probe lysosome viscosity and β-amyloid fibrils

Abstract

Alzheimer's disease (AD) is an incurable neurodegenerative disease. Better diagnosis of AD is extremely important for therapeutic interventions. The amyloid cascade hypothesis and its revised version identify insoluble β-amyloid deposition as a good diagnostic biomarker for AD. We hypothesize that lysosomal viscosity may also act as an auxiliary biomarker for AD based on literature research. Herein, we have successfully developed a FP chromophore analogue C25 as a dual-functional fluorescent probe which can respond effectively to the Aβ fibrils and enhanced lysosomal viscosity with distinguishable turn-on fluorescence signals around 570 nm and 600 nm, respectively. The probe C25 can also monitor the Aβ degradation in the lysosomes. The probe C25 can serve as a promising tool for developing early diagnosis and innovative therapeutics of AD.