Fluorescent ligand systems

A new approach to modeling multisite fluorescent enhancement data similar to the multisite quenching data treatment is proposed here. Incorporating fluorescence intensity changes and multicomponent mass balance equations describing the multiple site fluorescent ligand system is necessary. The new model uses the expression in equation 23 to describe... 

Dependent on the type of cell line and the type of labeled ligand in use, the binding of the targeted system to the cell membrane can be investigated qualitatively by CLSM or TEM at the isolated cell level or in monolayer systems. To quantify the amount of cell-bound fluorescent-labeled system, flow... 

This section indicates that is possible to transfect cells with GFP fusion proteins of the AR families. The co-localization of these proteins with fluorescent ligands provides a link that allows comparison with native cell systems that do not possess such useful tags but that bind the fluorescent ligands. However, an additional utility is provided by the ability to label receptors in native systems with GFP, which provides the opportunity for receptor translocation studies in native cells. This has been accomplished on two levels. First, by in vitro transfection of native tissues or cells (see Fig. 1C) and second by creating transgenic mice harboring the GFP-AR constructs (see Chapter 7). 

Generalizing equation 1 gives a model for the fluorescence of multi-ligand systems ... 

Zubieta and coworkers have recently taken advantage of the fluorescent and luminescent properties of organometallic complexes of rhenium (and technetium) comprising certain aromatic ligand systems (Fig. 2.2.6). The nonradioactive Re(CO)3 bioconjugates with a formyl peptide receptor-targeting peptide (flVlLF), enabeled visualization... 

Na Cs whereas Li does not induce any change. This stability order is confirmed by the salt concentration dependence of the fluorescence polarization. Furthermore, Na NMR spectroscopy reveals that the product system is stabilized by the addition of cations, suggesting that the OH group in schizophyllan and the phosphate anion in poly(U) synergistically form a specific ligand system for the cations. 

Synthetic strategy toward a biotin derivative with fluorescence properties after coordination of a tridentate ligand to the [Re(CO)3] core (James et al. 2006a) and a [2+1] mixed ligand system (Lo and Hui 2005)... 

Alternatively, let us consider another possible model that the rapid increase in fluorescence occurs on the formation of the binary complex SpLx and that the slow change in fluorescence occurs as SpL.K isomerizes to [SpLkJ. This model is described by scheme (b) below and has been proposed for a number of protein-ligand systems (e.g. see 3, 14). Note that it is not known which component in the complex changes conformation or whether both proteins are involved. 

The structure of the salen ligand system has been modified by using a dipyrrin -instead of the ethylenediamine-unit. The novel pentacoordinated dipyrrin-silicon complexes (31, see Scheme 4, and some of its derivatives) showed efficient red or near-IR fluorescence, and the structural interconversion between silanol and siloxane derivatives resulted in significant changes in the optical properties [150]. 

Swift, J. L., Heuff, R. F. and Cramb, D. T. (2006) A two-photon excitation fluorescence cross-correlation assay for a model ligand-receptor binding system using quantum dots. Biophys. J., 90, 1396-1410. 

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