The structure of biliproteins in insects differ slightly than those in plants and algae; they have a crystal structure and their chromophores are not covalently bound to the apoproteins.[1] Unlike phycobiliproteins whose chromophores are held in an extended arrangement by specific interactions between chromophores and proteins, the chromophore in insect biliproteins has a cyclic helical crystal structure in the protein-bound state, as found in studies of the biliprotein extracted from the large white butterfly.[9]