Allophycocyanins

Edington M D, Riter R E and Beck W F 1995 Evidence for coherent energy transfer in allophycocyanin trimers J. Phys. Chem. 99 15 699-704... 

Homoelle B J, Edington M D, Diffey W M and Beck W F 1998 Stimulated photon-echo and transientgrating studies of protein-matrix solvation dynamics and interexciton-state radiationless decay in a phycocyanin and allophycocyanin J. Phys. Chem. B 102 3044-52... 

When the proteins are in close proximity the Europium-cryptate emission can be absorbed by the acceptor (such as allophycocyanin [APC], or XL) which emits at a higher wavelength. When the two proteins are far apart, no fluorescence resonance energy transfer (FRET) occurs. 

FIGURE 19-43 A phycobilisome. In these highly structured assemblies found in cyanobacteria and red algae, phycobilin pigments bound to specific proteins form complexes called phycoerythrin (PE), phycocyanin (PC), and allophycocyanin (AP). The energy of photons absorbed by PE or PC is conveyed through AP (a phycocyanobilin-binding protein) to chlorophyll a of the reaction center by exciton transfer, a process discussed in the text. 

Figure 23-24 (A) Stereoscopic view of a hexameric (a(3)3 phycobiliprotein. (B) The (3 subunit of the complex with two molecules of bound phyco-ery throbilin and one of phy-courobilin. From Chang et al.279 (C) Schematic representation of a phycobilosome of a strain of the cyanobacterium Anabaena. Each disk in the structure contains an (a(3)3 phycobiliprotein. The circles marked AP are cross-sections of rods, each one composed of about four disks of allophycocyanin (AP).

Add phycoerythrin (PE) or allophycocyanin (APC) labeled or other fluorescent-labeled cell surface marker antibody to 50 pi of cells. Mix well and stain the cells at 4°C for 30 min. 

TPA tris(pyridylmethyl)amine allophycocyanin which emits... 

---