Skip to Content
Merck
  • A chemical screening approach reveals that indole fluorescence is quenched by pre-fibrillar but not fibrillar amyloid-beta.

A chemical screening approach reveals that indole fluorescence is quenched by pre-fibrillar but not fibrillar amyloid-beta.

Bioorganic & medicinal chemistry letters (2009-07-31)
Ashley A Reinke, Han Yiau Seh, Jason E Gestwicki
ABSTRACT

Aggregated amyloid-beta (Abeta) peptide is implicated in the pathology of Alzheimer's disease. In vitro and in vivo, these aggregates are found in a variety of morphologies, including globular oligomers and linear fibrils, which possess distinct biological activities. However, known chemical probes, including the dyes thioflavin T and Congo Red, appear to lack selectivity for specific amyloid structures. To identify molecules that might differentiate between these architectures, we employed a fluorescence-based interaction assay to screen a collection of 68 known Abeta ligands against pre-formed oligomers and fibrils. In these studies, we found that the fluorescence of five indole-based compounds was selectively quenched ( approximately 15%) in the presence of oligomers, but remained unchanged after addition of fibrils. These results suggest that indoles might be complementary to existing chemical probes for studying amyloid formation in vitro.

MATERIALS
Product Number
Brand
Product Description

Supelco
L-Tryptophan, certified reference material, TraceCERT®, Manufactured by: Sigma-Aldrich Production GmbH, Switzerland
Sigma-Aldrich
trans-Ferulic acid, ≥99%
Sigma-Aldrich
Benzophenone, purified by sublimation, ≥99%
Sigma-Aldrich
trans-Ferulic acid, 99%
Sigma-Aldrich
o-Vanillin, 99%
Sigma-Aldrich
Azure A eosinate, powder or crystals
Sigma-Aldrich
trans-Chalcone, 97%
Sigma-Aldrich
Tryptamine, ≥97%
Sigma-Aldrich
5-Hydroxy-1,4-naphthoquinone, 97%
Supelco
p-Anisaldehyde, analytical standard
Sigma-Aldrich
4,4′-Dihydroxybenzophenone, 99%
Sigma-Aldrich
Benzophenone, ReagentPlus®, 99%
Sigma-Aldrich
L-Tryptophan, BioUltra, ≥99.5% (NT)
Sigma-Aldrich
p-Anisaldehyde, ≥97.5%, FCC, FG
Sigma-Aldrich
p-Anisaldehyde, 98%
Sigma-Aldrich
Veratraldehyde, ≥98%, FG
Sigma-Aldrich
Tetrachloro-1,4-benzoquinone, 99%
Sigma-Aldrich
Azure A chloride, Dye content ≥70 %
Sigma-Aldrich
Anisaldehyde solution
Sigma-Aldrich
L-Tryptophan, reagent grade, ≥98% (HPLC)
Sigma-Aldrich
Methylene Blue Solution 1.4%(w/v)95%ethanol | 7220-79-3, 1.4 % (w/v) in 95% ethanol
Sigma-Aldrich
L-Tryptophan, from non-animal source, meets EP, JP, USP testing specifications, suitable for cell culture, 99.0-101.0%
Sigma-Aldrich
Melatonin, powder, ≥98% (TLC)
Sigma-Aldrich
3,4-Dimethoxybenzaldehyde, 99%
Sigma-Aldrich
Myricetin, ≥96.0% (HPLC)
Sigma-Aldrich
Myricetin, ≥96.0%, crystalline
Sigma-Aldrich
(−)-Epigallocatechin gallate, ≥95%
Sigma-Aldrich
Resveratrol, ≥99% (HPLC)
Supelco
Resveratrol, analytical standard
Supelco
Benzophenone, analytical standard