Donor-acceptor fusion

For a first approximation, k can be simply calculated by dividing by I for a donor-acceptor fusion construct, because both quantities are corrected for overlap and FRET. Note however that this requires acceptor concentration, we simply find ... 

Figure 2 Imaging protein-protein interactions by FRET and BRET, (a) Diagram illustrating FRET between the donor CFP-fusion and the acceptor YFP-fusion. (b) Detection of protein-protein interaction between X and Y by BRET using the Renilla luciferase (Rluc) as a bioluminescent donor and GFP as a fluorescent acceptor. The substrate for Rluc is deep blue coelenterazine. Constructs not drawn to scale.

As previously noted, discrete assemblies based on 1-dimensional H-bonded motifs, also termed a-networks, may be obtained by covalently tethering the H-bonding recognition arrays or by their fusion to yield Janus molecules (Fig. 2). The information manifested in the relative orientation (120°) and juxtaposition of H-bonding donor/acceptor sites (DAD/ADA), in the specific case of 5 and 6, may generate three types of association a linear ribbon or tape, a H-bonded macrocycle and an intermediate wavy ribbon or crinkled tape [46]. These structures have been characterized in the solid state by X-ray crystallographic analysis. Homochiral crinkled tapes are formed in the course... 

Figure 2. Genetic aberrations observed in HAT genes, (a) Schematic representation of a balanced chromosomal translocation. These translocations result in the formation two new fusion genes, which can give rise to one or two fusion proteins, (b) Examples of nonsense (RTS patient RT163.1), missense (RT209.1), deletion (followed by frame shift RT231.1) mutations, as well as sphee site acceptor (RT211.3) or splice site donor (RT39.1) mutations...

Membranes fusion can be studied using the energy-transfer mechanism. In fact, membrane vesicles labeled with both NBD and rhodamine probes are fused with unlabeled vesicles. In the labeled vesicles, upon excitation of NBD at 470 nm, emission from rhodamine is observed at 585 nm as a result of energy transfer from NBD to rhodamine. The average distance separating the donor from the acceptor molecules increases with fusion of the vesicules, thereby decreasing the energy-transfer efficiency (Struck et al. 1981). 

Proper kinetic and thermodynamic meshing of the reactants is necessary for hydride transfer from a donor to an acceptor. There are at least three obviously different mechanisms by which hydride equivalents can be transferred. These are (i) concerted transfer of the proton and two electrons (equation 5) (ii) homolytic cleavage of the carbon-hydrogen bond followed by subsequent transfer of an electron (equation 6) and (iii) initial loss of a proton followed by transfer of two electrons, either together or stepwise (equation 7). Fusion of pathways is imaginable, (tependent on the structures of the participating molecules and possibilities for catalysis. 

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