Fluorescein-based amino acids for solid phase synthesis of fluorogenic protease substrates

Bioorg Med Chem. 2006 Apr 15;14(8):2559-68. doi: 10.1016/j.bmc.2005.11.037. Epub 2005 Dec 27.

Abstract

An efficient synthesis of new type fluorescent amino acids is described. The Fmoc-protected dyes can be prepared in a four-step procedure with approximately 30% overall yield from aminofluoresceins and other inexpensive commercially available precursors. The dyes are much more photostable compared to fluorescein and exhibit constant pH-independent fluorescence that is advantageous in biological applications. The Fmoc-protected fluorescent amino acids are ready for use in solid phase peptide synthesis. As a proof of concept, a fluorogenic papain substrate was synthesized and employed for on-bead detection of the protease activity. By using a novel technique for quantitative analysis of bead fluorescence, a approximately 2.7-fold increase in mean bead brightness was measured and was attributed to substrate cleavage by papain. The new type fluorescent amino acids seem to be a promising tool for the synthesis of fluorescent peptide ligands and fluorogenic protease substrates.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acids / metabolism*
  • Fluorescein / chemistry*
  • Hydrolysis
  • Magnetic Resonance Spectroscopy
  • Mass Spectrometry
  • Peptide Hydrolases / metabolism*
  • Substrate Specificity

Substances

  • Amino Acids
  • Peptide Hydrolases
  • Fluorescein