Luminescence of deoxyhemocyanin and deoxytyrosinase.

The deoxy form of hemocyanins and tyrosinases from certain species displays a weak low-energy luminescence when solutions of the protein are irradiated with light at approximately 290 nm. The emission most likely results from a copper-to-imidazole charge transfer state as shown by studies with a synthetic copper(I) complex having three imidazole ligands.