MilliporeSigma
  • 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
Salicylic acid, certified reference material, TraceCERT®, Manufactured by: Sigma-Aldrich Production GmbH, Switzerland
Sigma-Aldrich
Salicylic acid, ACS reagent, ≥99.0%
Sigma-Aldrich
Salicylic acid, meets analytical specification of Ph. Eur., BP, USP, 99.5-100.5% (calc. to the dried substance)
Sigma-Aldrich
Salicylic acid, ReagentPlus®, ≥99%
Sigma-Aldrich
Salicylic acid, puriss. p.a., ≥99.0% (T)
Sigma-Aldrich
Salicylic acid, ≥99%, FG
Sigma-Aldrich
Salicylic acid, suitable for plant cell culture
Sigma-Aldrich
Salicylic acid, BioXtra, ≥99.0%
Supelco
(−)-Epicatechin, analytical standard
Supelco
Mettler-Toledo Calibration substance ME 18870, Benzophenone, for the calibration of the thermosystem 900, traceable to primary standards (LGC)
Sigma-Aldrich
Rosmarinic acid, 96%
Sigma-Aldrich
Acetophenone, ≥98%, FG
Sigma-Aldrich
Apigenin, ≥95.0% (HPLC)
Sigma-Aldrich
Nordihydroguaiaretic acid, ≥97.0% (HPLC)
Sigma-Aldrich
Anthrone, ACS reagent, 97%
Sigma-Aldrich
Indole-3-carboxaldehyde, 97%
Sigma-Aldrich
3-Hydroxybenzaldehyde, ≥99%
Sigma-Aldrich
Acetophenone, ReagentPlus®, 99%
Sigma-Aldrich
Kaempferol, ≥97.0% (HPLC)
Sigma-Aldrich
Indole, ≥99%
Sigma-Aldrich
Bis(4-hydroxyphenyl)methane, 98%
Sigma-Aldrich
trans-3-Hydroxycinnamic acid, 99%
Sigma-Aldrich
Indole, ≥99%, FG
Sigma-Aldrich
Acetophenone, puriss. p.a., ≥99.0% (GC)