Phycoerythrin

Phycoerythrin is a type of phycobiliprotein, a family of water-soluble proteins present in cyanobacteria and red algae. It is a red protein-pigment complex from the light-harvesting phycobiliprotein family, along with allophycocyanin and phycocyanin. It is an accessory pigment to chlorophyll. All phycobiliproteins are composed of a protein part and a nonprotein, chromophore, part.

Structure

Phycoerythrin is composed of at least three different subunits and occurs in two forms: B-phycoerythrin, which is found in red algae, and C-phycoerythrin, which is found in cyanobacteria. The protein is present in the thylakoid lumen and is involved in directing light energy to chlorophyll.

Function

Phycoerythrin absorbs light best in the wavelength range of 540 to 570 nm, and emits light in the range of 570 to 580 nm. It captures light energy and passes it on to chlorophylls during photosynthesis. The energy absorption and fluorescence emission makes phycoerythrin a useful tool in research. It is used as a tracer molecule in fluorescence microscopy, flow cytometry, fluorescence correlation spectroscopy and ELISA assays.

See also

• Phycobilin
• Phycobilisome
• Phycocyanobilin
• Phycoerythrobilin

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  Phycobilisome structure
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  B-phycoerythrin structure
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  Phycoerythrobilin structure
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  Gracilaria
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  Phycoerythrin 545
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  R-phycoerythrin part 1
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  R-phycoerythrin part 2
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  Pycoerythrin spectra
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  RPE exemplified comparison