Phycobiliprotein

Phycobiliproteins are water-soluble proteins present in cyanobacteria and certain algae (rhodophytes, cryptomonads, glaucocystophytes). They capture light energy, which is then passed on to chlorophylls during photosynthesis. Phycobiliproteins are formed of a complex between proteins and covalently bound phycobilins that act as chromophores (the light-capturing part).^[1] They are most important constituents of the phycobilisomes.

Phycobilisome structure

Major phycobiliproteins

Characteristics

Phycobiliproteins demonstrate superior fluorescent properties compared to small organic fluorophores, especially when high sensitivity or multicolor detection required :

• Broad and high absorption of light suits many light sources
• Very intense emission of light: 10-20 times brighter than small organic fluorophores
• Relative large Stokes shift gives low background, and allows multicolor detections.
• Excitation and emission spectra do not overlap compared to conventional organic dyes.
• Can be used in tandem (simultaneous use by FRET) with conventional chromophores (i.e. PE and FITC, or APC and SR101 with the same light source).
• Longer fluorescence retention period.
• High water solubility

Applications

Phycobiliproteins allow very high detection sensitivity, and can be used in various fluorescence based techniques fluorimetric microplate assays Archived 2018-03-18 at the Wayback Machine,^[7][8][9] FISH and multicolor detection.

They are under development for use in artificial photosynthesis, limited by the relatively low conversion efficiency of 4-5%.^[10]

References

1. Aizpuru, Aitor; González-Sánchez, Armando (2024-07-20). "Traditional and new trend strategies to enhance pigment contents in microalgae". World Journal of Microbiology and Biotechnology. 40 (9): 272. doi:10.1007/s11274-024-04070-3. ISSN 1573-0972. PMC 11271434. PMID 39030303.
2. Contreras-Martel, C.; Legrand, P.; Piras, C.; Vernede, X.; et al. (2000-05-09). "Crystal structure of R-phycoerythrin at 2.2 angstroms". RCSB Protein Data Bank (PDB). doi:10.2210/pdb1eyx/pdb. PDB ID: 1EYX. Retrieved 11 October 2012. {{cite journal}}: Cite journal requires |journal= (help)
3. Contreras-Martel C, Martinez-Oyanedel J, Bunster M, Legrand P, Piras C, Vernede X, Fontecilla-Camps JC (January 2001). "Crystallization and 2.2 A resolution structure of R-phycoerythrin from Gracilaria chilensis: a case of perfect hemihedral twinning". Acta Crystallographica D. 57 (Pt 1): 52–60. doi:10.1107/S0907444900015274. PMID 11134927. S2CID 216930. PDB ID: 1EYX.
4. Image created with RasTop (Molecular Visualization Software).
5. Camara-Artigas, A. (2011-12-16). "Crystal Structure of the B-phycoerythrin from the red algae Porphyridium cruentum at pH8". RCSB Protein Data Bank (PDB). doi:10.2210/pdb3v57/pdb. PDB ID: 3V57. Retrieved 12 October 2012. {{cite journal}}: Cite journal requires |journal= (help)
6. Camara-Artigas A, Bacarizo J, Andujar-Sanchez M, Ortiz-Salmeron E, Mesa-Valle C, Cuadri C, Martin-Garcia JM, Martinez-Rodriguez S, Mazzuca-Sobczuk T, Ibañez MJ, Allen JP (October 2012). "pH-dependent structural conformations of B-phycoerythrin from Porphyridium cruentum". The FEBS Journal. 279 (19): 3680–3691. doi:10.1111/j.1742-4658.2012.08730.x. PMID 22863205. S2CID 31253970. PDB ID: 3V57.
7. "MicroPlate Detection comparison between SureLight P-3L, other fluorophores and enzymatic detection Table 1: Comparison of honeypot with other detection methods". Columbia Biosciences. 2010. doi:10.7717/peerj-cs.350/table-1.
8. "Flow Cytometry" (PDF). Archived from the original (PDF) on 2018-03-18. Retrieved 2014-06-07.
9. Telford, William G; Moss, Mark W; Morseman, John P; Allnutt, F.C.Thomas (August 2001). "Cyanobacterial stabilized phycobilisomes as fluorochromes for extracellular antigen detection by flow cytometry". Journal of Immunological Methods. 254 (1–2): 13–30. doi:10.1016/s0022-1759(01)00367-2. ISSN 0022-1759. PMID 11406150.
10. Lavars, Nick (2021-10-19). "Encasing algae triples the efficiency of artificial photosynthesis". New Atlas. Retrieved 2021-10-24.