A highly sensitive peptide substrate for detecting two Aβ-degrading enzymes: Neprilysin and insulin-degrading enzyme

Po Ting Chen, Tai Yan Liao, Chaur Jong Hu, Shu Ting Wu, Steven S S Wang, Rita P Y Chen

Research output: Contribution to journalArticle

15 Citations (Scopus)

Abstract

Neprilysin has been singled out as the most promising candidate for use in the degradation of Aβ as a therapy for Alzheimer's disease. In this study, a quenched fluorogenic peptide substrate containing the first seven residues of the Aβ peptide plus a C-terminal Cysteine residue was synthesized to detect neprilysin activity. A fluorophore was attached to the C-terminal Cysteine and its fluorescence was quenched by a quencher linked to the N-terminus of the peptide. When this peptide substrate was degraded by an endopeptidase, fluorescence was produced and proved to be a sensitive detection system for endopeptidase activity. Our results showed that this assay system was extremely sensitive to neprilysin and insulin-degrading enzyme, but insensitive, or much less sensitive, to other Aβ-degrading enzymes. As low as 0.1. nM of neprilysin and 0.2. nM of insulin-degrading enzyme can be detected.

Original languageEnglish
Pages (from-to)57-62
Number of pages6
JournalJournal of Neuroscience Methods
Volume190
Issue number1
DOIs
Publication statusPublished - Jun 2010

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Keywords

  • Alzheimer
  • Amyloid
  • Digestion
  • Fluorescence
  • Insulin-degrading enzyme
  • Neprilysin
  • Quench

ASJC Scopus subject areas

  • Neuroscience(all)
  • Medicine(all)

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