Dual-Readout Tyrosinase Activity Assay Facilitated by a Chromo-Fluorogenic Reaction between Catechols and Naphthoresorcin

Anal Chem. 2020 Jan 21;92(2):2316-2322. doi: 10.1021/acs.analchem.9b05204. Epub 2020 Jan 3.

Abstract

Analyte-responsive chromo-fluorogenic reactions under accessible conditions are important for designing small-molecule spectroscopic probes. We describe a series of newly constructed motifs based on the chromo-fluorogenic reaction between catechol derivatives (typically hydroxytyrosol, dopamine, and levodopa) and naphthoresorcin (NR) in aqueous solution under ambient conditions. The weakly absorptive and fluorogenic catechols/NR was converted to products having visible absorption and bright fluorescence within several minutes. The chromo-fluorophores produced from this reaction had a maximum absorbance at 458 nm and emission at 480 nm with high fluorescence quantum yields (30-84%). Inspired by the tyrosinase-catalyzed hydroxylation of monophenols to catechols, the tyrosinase-enabled chromo-fluorogenic reaction was verified by using monophenol (typically tyrosol) as the substrate. In this regard, a dual-readout tyrosinase activity assay was developed by virtue of the in situ "turn-on" optical signals. Furthermore, a test of tyrosinase inhibition, by using a common inhibitor kojic acid, demonstrated the potential of the chromo-fluorogenic reaction for developing other tyrosinase related assays and signal transduction.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Agaricales / enzymology
  • Catechols / chemistry
  • Catechols / metabolism*
  • Fluorescent Dyes / chemistry
  • Fluorescent Dyes / metabolism*
  • Molecular Structure
  • Monophenol Monooxygenase / analysis
  • Monophenol Monooxygenase / metabolism*
  • Naphthalenes / chemistry
  • Naphthalenes / metabolism*
  • Resorcinols / chemistry
  • Resorcinols / metabolism*

Substances

  • Catechols
  • Fluorescent Dyes
  • Naphthalenes
  • Resorcinols
  • naphthalene
  • Monophenol Monooxygenase
  • resorcinol