Lanthanides resonance energy transfer

The intramolecular distances measured at room temperature with the AEDANS FITC pair were similar in the Ca2Ei and E2V states [297]. Ca and lanthanides are expected to stabilize the Ej conformation of the Ca -ATPase, since they induce a similar crystal form of Ca -ATPase [119,157] and have similar effects on the tryptophan fluorescence [151] and on the trypsin sensitivity of Ca -ATPase [119,120]. It is also likely that the vanadate-stabilized E2V state is similar to the p2 P state stabilized by Pi [418]. Therefore the absence of significant difference in the resonance energy transfer distances between the two states implies that the structural differences between the two conformations at sites recorded by currently available probes, fall within the considerable error of resonance energy transfer measurements. Even if these distances would vary by as much as 5 A the difference between the two conformations could not be established reliably. 

Charbonniere LJ, Hildebrandt N, Ziessel RF, Lohmannsroben HG (2006) Lanthanides to quantum dots resonance energy transfer in time-resolved fluoro-immunoassays and luminescence microscopy. J Am Chem Soc 128 12800-12809... 

Selvin, P. R. (1996). Lanthanide-based resonance energy transfer. IEEE Journal of selected topics in quantum electronics Lasers Biol. 2, 1077-1087. 

Conclusions from the reference 28 review article are as follows (1) Several models backed by experiment place S4 near the groove between adjacent subunits, while the MacKinnon group model places S4 near the periphery of the protein (2) lanthanide-based resonance energy transfer (LRET) places two S4 residues in segments across the tetramer from each other at a distance of 45 A (3) a method based on tethered quaternary ammonium pore blockers places the extracellular ends of the SI and S3 helices further away from the ion conduction pore than the S3-S4 linker, arguing that the S4 helix resides... 

Xiao, M. Selvin, P. R. Quantum yields of luminescent lanthanide chelates and far-red dyes measured by resonance energy transfer. J. Am. Chem. Soc. 2001,123, 7067-7073. 

Vogel, K.W. and K.L. Vedvik. 2006. Improving lanthanide-based resonance energy transfer detection by increasing donor-acceptor distances. J. Biomol. Screen. 11, 439 143. 

Another example of improved sensitivity due to modulation of lanthanide photophysics by ancillary ligands can be found in the europium and terbiiun chelates used in time-resolved fluorescence resonance energy transfer (TR-FRET) immunoassays (100,101). Due to their line-type emissions and long decay times, the lanthanide chelate is used as a donor, with some visible-absorbing dye such as Alexa 647 or a rhodamine derivative as the acceptor. Without the helper ligand, the lanthanides would be unprotected from solvent and have much shorter decay times, making them unsuitable for such an assay. 

Single lanthanide-doped oxide nanoparticles as donors in fluorescence resonance energy transfer experiments. J. Phys. Chem. 2006 110 19264-19270. 88. 

Note As for TRF, the term fluorescence is in fact misused in TR-FRET. In the spectroscopic Hteratirre, resonance energy transfer from a long-Hfetime probe such as a lanthanide chelate is termed LRET (luminescence RET) [121]. 

Problems and Future Directions Luminescence Resonance Energy Transfer Using Lanthanide Chelates... 

Fluorescence resonance energy transfer (FRET) and fluorescence quenching for lanthanide labels... 

Particulate lanthanide reporters can be utilized as donors in resonant energy transfer to short-Ufetime fluorescent acceptors, enabling homogeneous assay technology. Temporal resolution eliminates autofluorescence and the direct fluorescence of an... 

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