A Novel Type of Luciferin from the Siberian Luminous Earthworm Fridericia heliota: Structure Elucidation by Spectral Studies and Total Synthesis

Abstract

We report structure elucidation and synthesis of the luciferin from the recently discovered luminous earthworm Fridericia heliota. This luciferin represents a key component of a novel ATP-dependent bioluminescence system. The UV, fluorescence, NMR and HRMS spectral studies were performed on 5 mkg of the isolated substance, and gave four isomeric structures, conforming with spectral data. These isomers were chemically synthesized and one of them was found to produce light in the reaction with a protein extract from Fridericia. The novel luciferin was found to have an unusual deeply modified peptidic nature, implying an unprecedented mechanism of action.

Novel Mechanism of Bioluminescence: Oxidative Decarboxylation of a Moiety Adjacent to the Light Emitter of Fridericia Luciferin

“…A downfield shift of the CompX H‐3 proton by approximately 0.2 ppm was also observed, while all other protons remained intact and showed unchanged NMR signals. Taken together, these data provide unambiguous evidence that Fridericia oxyluciferin is produced through oxidative decarboxylation of the lysine moiety, contrary to our initial hypothesis that the oxalate fragment is oxidized during bioluminescence 2…”

“…We recently reported the structure of a novel luciferin from the Siberian bioluminescent earthworm Fridericia heliota. 2 We found this luciferin to be a key component of a novel ATP‐dependent bioluminescent system, along with a specific luciferase, ATP, Mg 2+ ions, and molecular oxygen3 The Fridericia luciferin turned out to be an unusual peptide formed from oxalic acid, L ‐lysine, modified tyrosine (CompX4), and γ‐aminobutyric acid residues. Herein, we report the structural elucidation of the Fridericia luciferin oxidation product, i.e., the oxyluciferin.…”

“…Oxyluciferin was prepared by mixing 0.18 mg of synthetic Fridericia luciferin2 with excess ATP and crude Fridericia luciferase obtained through partial purification of protein extract from 40 g of the worm biomass5 (Scheme , see the Supporting Information for details). The reaction mixture produced constant eye‐visible luminescence and the reaction course was monitored by HPLC analysis of aliquots (Figure 1), which showed formation of a major product of luciferin oxidation with a retention time of 18.2 min.…”

Synthetic analogue of Fridericia luciferin with improved spectral properties

“…New ATP-dependent BL system of Fridericia heliota earthworm was described in 2014 [5]. The BL maximum of Fridericia luciferin (I) is at 478 nm.…”

Entwicklung eines weitgespannten Sandwichdeckensystems mit integrierter Haustechnik in Verbundbauweise

“…Indeed, the difficulty of getting RX structures from biological systems limits the number of available BL luminophores, whereas many of them are deemed very unstable in pure form, and their structures remain uncertain or are unknown. For instance, although the BL of the Siberian glowworm ( Fridericia heliota ) and some fungal species have been known for centuries, the structures of their substrates were characterized only recently 6–8. The protocols for cases in which synthetic procedures are available9,10 are laborious and cost ineffective, which greatly limits prospects for systematic studies of the related CL and BL mechanisms.…”