ABSTRACT
Phycobiliproteins (phykos (Gr.), seaweed) are a family of proteins with covalently attached linear tetrapyrrole prosthetic groups. These prosthetic groups are called bilins because of their close structural relationship to the well-known bile pigments of humans, biliverdin and bilirubin (Lemberg and Legge, 1949). The conformational and steric constraints imposed upon the bilins and their environment within the native phycobiliproteins endow these tetrapyrroles with special spectroscopic properties which are manifested by the brilliant colours and vivid fluorescence of these proteins.
