BIOSYNTHESIS OF CYPRIDINA LUCIFERIN FROM FREE AMINO ACIDS IN CYPRIDINA (VARGULA) HILGENDORFII

摘要

The luminous marine ostracod Cypridina hilgendorfii (presently Vargula hilgendorfii) lives in the Japanese coast. The luminescence system of V. hilgendorfii has been investigated extensively, since Harvey reported the luciferin-luciferase reaction in 1917. When the specimen is stimulated physically or electronically, it expels Cypridina luciferin and luciferase directly into the seawater to produce a brilliant bluish luminescence (kmM= 460 nm). The isolation, structural determination and total synthesis of Cypridina luciferin have been achieved by Kishi et al.,w and they proposed that Cypridina luciferin may be biosynthesized from three amino acids or their equivalents: arginine, isoleucine and tryptophan (or tryptamine). However the biosynthetic pathway of Cypridina luciferin has not been proven. Recently, we identified that L-tryptophan is a synthetic component of Cypridina luciferin by feeding experiments using deuterium labeled L-tryptophan.3 In this study, other possible amino acids were examined and we concluded that Cypridina luciferin is biosynthesized from L-tryptophan, L-arginine, L-isoleucine, but not tryptamine.