Novel peptide chemistry in terrestrial animals: natural luciferin analogues from the bioluminescent earthworm Fridericia heliota.

ABSTRACT

We report isolation and structure elucidation of AsLn5, AsLn7, AsLn11 and AsLn12 novel luciferin analogs from the bioluminescent earthworm Fridericia heliota. They were found to be highly unusual modified peptides, comprising either of the two tyrosine-derived chromophores, CompX or CompY and a set of amino acids, including threonine, gamma-aminobutyric acid, homoarginine, and unsymmetrical N,N-dimethylarginine. These natural compounds represent a unique peptide chemistry found in terrestrial animals and rise novel questions concerning their biosynthetic origin.