biology

Introduction of Phycobiliproteins

Phycobiliproteins are water-soluble fluorescent proteins derived from cyanobacteria and Eukaryotic algae. In these organisms they are used as accessory or antenna pigments for photosynthetic light collection. They absorb energy in portions of the visible spectrum that are poorly utilized by chlorophyll and through fluorescence energy transfer, convey the energy to chlorophyll at the photosynthetic reaction centre. Phycobiliproteins are easily conjugated to streptavidin and antibodies using traditional methods. Browse our Product Catalogue to find a wide selection of Phycobiliproteins and Phycobiliprotein conjugates. Far East Bio-Tec Co. manufacturers the algae by fermentation in two locations in California. In this way cells can be harvested and Phycobiliproteins purified before any deterioration of the molecule occurs. They are very pure. By always harvesting the cells at the same time, the cells are remarkably consistent lot to lot; hence the Phycobiliproteins are remarkably consistent lot to lot.

 


What do you Know about R-phycoerythrin?

 

R-Phycoerythrin, or PE, is useful in the laboratory as a fluorescence-based indicator for the presence of cyanobacteria and for labeling antibodies in a technique called immunofluorescence, among other applications. There are also other types of phycoerythrins, such as B-Phycoerythrin, which has slightly different spectral properties. B-Phycoerythrin absorbs strongly at about 545 nm (slightly yellowish green) and emits strongly at 572 nm (yellow) instead and could be better suited for some instruments. B-Phycoerythrin may also be less "sticky" than R-Phycoerythrin and contributes less to background signal due to non-specific binding in certain applications.

 

Phycoerythrins except phycoerythrin 545 (PE545) are composed of (αβ) monomers assembled into disc-shaped (αβ)6 hexamers or (αβ)3 trimers with 32 or 3 symmetry and enclosing central channel. In phycobilisomes (PBS) each trimer or hexamer contains at least one linker protein located in central channel. B-phycoerythrin (B-PE) and R-phycoerythrin (R-PE) from red algae in addition to α and β chains have third, γ subunit combining linker and light-harvesting functions, because bears chromophores.

 

This fluorochrome is a member of the phycobiliprotein family of proteins isolated from the marine algae Porphyra tenera or Gastroclonium coulterii. Fluorochrome-labeled reagents have high resolution and are therefore advantageous in immunological assays, such as live cell staining, double-labeling techniques and cell sorting procedures. The strong absorption bands of the R-Phycoerythrin are in the visible region of the spectrum, extending from the green to the far-red wavelengths. The absorbance spectra extends over a broad range of potential excitation wavelengths, allowing for versatility in the excitation source and creating large Stokes shifts, thus minimizing interference from Rayleigh-scattered light.