Identification of the Luciferin–Luciferase System and Quantification of Coelenterazine by Mass Spectrometry in the Deep‐Sea Luminous Ostracod Conchoecia pseudodiscophora

The bioluminescence system of the ostracod Conchoecia pseudodiscophora , which is abundant in the Sea of Japan, has been characterized. The luminescence ( λ max =463 nm) is produced by a luciferin–luciferase reaction, and the luciferin has been identified as coelenterazine. Coelenterazine, coelenteramide, and coelenteramine from C. pseudodiscophora were quantified by LC‐ESI‐MS/MS analysis. The coelenterazine content was estimated to be approximately 230 pg per animal by using a calibration curve of synthetic coelenterazine. The reaction between homogenates of C. pseudodiscophora and synthetic coelenterazine showed luminescence activity; this suggests that a coelenterazine‐type luciferase is present.