Identification of a novel oxidation product from yellow fluorophore in the complex of apoPholasin and dehydrocoelenterazine

Bioorg Med Chem Lett. 2020 Oct 1;30(19):127435. doi: 10.1016/j.bmcl.2020.127435. Epub 2020 Jul 24.

Abstract

The complex of the recombinant fusion protein of apoPholasin and glutathione S-transferase (GST-apoPholasin) with non-fluorescent dehydrocoelenterazine (dCTZ) (GST-apoPholasin/dCTZ complex) shows yellow fluorescence at 539 nm by excitation at 430 nm. The GST-apoPholasin/dCTZ complex with a fluorophore (dCTZ*) has considerably weak luminescence activity, converting slowly to a blue fluorescence protein with the emission peak at 430 nm. The main oxidation products from dCTZ* for blue fluorescence were identified as coelenteramine (CTM) and an unreported pyrazine derivative, 3-benzyl-5-(4-hydroxyphenyl)pyrazin-2(1H)-one (CTO) that was confirmed by chemical synthesis.

Keywords: Coelenteramide; Coelenteramine; Coelenterazine; Photoproteins; Reactive oxygen.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Apoproteins / chemistry*
  • Color
  • Firefly Luciferin / chemistry*
  • Fluorescence
  • Glutathione Transferase / chemistry*
  • Imidazoles / chemical synthesis*
  • Oxidation-Reduction
  • Pyrazines / chemical synthesis*

Substances

  • Apoproteins
  • Imidazoles
  • Pyrazines
  • dehydrocoelenterazine
  • Firefly Luciferin
  • pholasin
  • Glutathione Transferase