Phycobiliproteins energy transfer

Glazer, A.N., and Stryer, L. (1983) Fluorescent tandem phycobiliprotein conjugates Emission wavelength shifting by energy transfer. Biophys. /. 43, 383-386. 

P. Khanna, Energy transfer immunoassays using phycobiliproteins. Presentation at Conference of Phycobiliprotein in Biology and Medicine, Seattle, Washington, September 9-10, 1985. 

Table 1. Examples drawn from four classes of phycobiliproteins, allophycocyanin (APC), phycocyanin (PC), phycoerythrocyanin (PEC), and phycoerythrin (PE), arranged in the order of decreasing wavelengths of their major absorption bands. and x " are the peak wavelengths of the principal (and minor) absorption and fluorescence bands, respectively. See List of Abbreviations for the full names of the different phycobiliproteins. Table adapted from Glazer (1982) Phycobilisomes Structure and dynamics. Annu Rev Microbiology 36 178 and Glazer (1989) Light guides. Directionai energy transfer in a photosynthetic antenna. J Biol Chem. 264 2.

Swanson, R, V, Glazer, A, N, (1990), Phycobiliprotein methylation. Effect of the y-N-methy-lasparagine residue on energy transfer in phycocyanin and the phycobilisome. J. Mol. Biol. 214, 787-796. 

The conditions for efficient energy transfer by inductive resonance are that the phycobiliprotein chromophore (the donor) and the chlorophyll antenna molecule (the acceptor) be in close proximity, usually about 5 nm apart. The "resonance" part is how the frequency of the flurorescence emis-... 

Carotenoid is the main light harvesting antenna pigment of RC II in some algal phyla [1]. Energy transfer process from carotenoid to chi is less characterized, compared with the situation of chi or phycobiliproteins. The electron exchange mechanism [2] is proposed for this process, contrary to the case of Forster mechanism [3] for chi or phycobiliproteins. 

Peridinin, the main light harvesting pigment in dinoflagellates [l], are associated with two kinds of pigment protein complexes water-soluble and membrane-bound complexes [1]. Both of them are functional in photosynthesis. Energy transfer mechanism in this complex, however, has not yet been elucidated. This is mainly due to the lack of information on the time-dependent behaviour of component(s) and fluorescence properties of carotenoid, which are critical for the analysis, as shown for the case of chi or phycobiliproteins [4,6]. 

Schmitt F, Maksimov E, Suedmeyer H, Jeyasangar V, Theiss C, Paschenko V, Eichler H, Renger G (2011) Time resolved temperature switchable excitation energy transfer processes between CdSe/ZnS nanocrystals and phycobiliprotein anteima from Acaryochloris marina. Photonic Nanostruct 9(2) 190... 

Phycobiliproteins associate as heterodimers of a and P monomeric subunits that, in turn aggregate into trimeric aP)i and hexameric discs aP)(,- The rod structure characteristic of PBSs is stabilized by non-pigmented linker polypeptides (L) specifically associated with each type of phycobiliprotein (Table 2) to optimize their absorption and energy transfer properties. 

The participation of the phycobiliproteins in the absorption ofphotokinetically active light has been demonstrated above. Peaks of around 565 and 615 nm in the action spectra indicate the involvement of C-phycoerythrin andC-phycocanin. These pigments transfer energy to the reaction center of PS II and suggest the participation of the non-cyclic electron transport and coupled phosphorylation. 

A third and relatively new application of FRET is the generation of new compound dyes with spectral characteristics that combine the best of both dyes. The idea is to attach covalently a donor and acceptor together in close proximity to one another. In the simplest case, where the absorption or emission properties of the individual dyes do not change, the absorption characteristic of the compound dye is the sum of the two individual dyes. At the same time, the emission is dominated by the acceptor since almost all of the energy absorbed by the donor is transferred to the acceptor. This results in dyes having potentially large Stokes shifts (the sum of the donor and acceptor Stokes shifts) and excellent quantum yields. So far, this work has mainly been applied to phycobiliproteins and DNA dyes. " ... 

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