Cypridina luciferin + O2 = CO2 + hnu + oxidized Cypridina luciferin The cysteine residues presumably exist in intramolecular disulfide bridges. The N-terminus is blocked. 60 kcal/mol are required for the blue emission of light (460 nm) due to the oxidation of luciferin via a dioxetanone intermediate, in which the excited state oxyluciferin bound to luciferase is the emitter.