Phycoerythrin
Phycoerythrin is a red accessory pigment of photosynthesis that occurs in cyanobacteria (blue algae) and red algae . It consists of a protein complex that carries a chromophoric group that coordinates copper as the central atom. Phycoerythrin belongs together with phycocyanin to the phycobiliproteins . Its absorption spectrum shows absorption maxima at wavelengths of 496 nm, 529 to 534 nm and 555 nm. Phycobilins absorb light quanta of wavelengths at which chlorophyllhas no absorption. Phycoerythrin transmits the energy to the chlorophyll via phycocyanin. The quantum efficiency of phycobilins is even higher than that of chlorophyll.
In Rhodomonas the complex consists of a tetramer of 2 of 4 different α-units and 2 identical β-units.
Algae and cyanobacteria that have this pigment (e.g. Planktothrix rubescens ) can use the weak light area in the depths of water , where only the shorter-wave blue light occurs in sufficient intensity.
Certain forms of phycoerythrin are used as fluorescent dyes in biological and biomedical research in various laboratory methods . These methods include, for example, flow cytometry and immunofluorescence .
literature
- ^ OVS Heath: Physiology of Photosynthesis. Thieme, 1972. ISBN 3-13-490101-3 .
- ↑ UniProt P30942