Phycobiliprotein

Phycobiliproteins are water-soluble proteins present in cyanobacteria and certain algae (rhodophytes, cryptomonads, glaucocystophytes).

Phycobiliproteins are formed of a complex between proteins and covalently bound phycobilins that act as chromophores (the light-capturing part).

(Phycobiliprotein overview information) (563 nm) 2.33 106 Because of its high quantum yield, B-PE is considered the world's brightest fluorophore.

It is compatible with commonly available lasers and gives exceptional results in flow cytometry, Luminex and immunofluorescent staining.

Structural Characteristics Allophycocyanin can be isolated from various species of red or blue-green algae, each producing slightly different forms of the molecule.

Phycobilisome structure
The crystal structure of R-phycoerythrin from red algae Gracilaria chilensis ( PDB ID: 1EYX [ 2 ] [ 3 ] [ 4 ] ) - basic oligomer ( α β γ ) 2 (so called asymmetric unit). It contains phycocyanobilin , biliverdine IX alpha , phycourobilin , N-methyl asparagine , SO 4 2− . One fragment of γ chain is red, second one white because it is not considered as alpha helix despite identical aminoacid sequence.
The crystal structure of B-phycoerythrin from red algae Porphyridium cruentum ( PDB ID: 3V57 [ 5 ] [ 6 ] [ 4 ] ). The asymmetric unit ( α β ) 2 on the left and assumed biological molecule ( α β ) 3 . It contains phycoerythrobilin , N-methyl asparagine and SO 4 2− .
Allophycocyanin dodekamer + 12 phycocyanobilin (green), Gloeobacter violaceus