Fluorophores fluorescent ligands

Fluorescence staining for flow cytometric analysis falls into three categories methods in which a fluorescent ligand accumulates on or within the cell (see Chapters 36,38) methods that require the ligand to interact with a cellular component to release the fluorophore or result in light emission (see Chapters 34,39) and methods that rely on fluorophore-coupled antibody binding (see Chapters 32,33). 

Coordination of NO to the iron results in labilization of the quinoline moiety and fluorescence decrease [94], Other NO sensors are based on Fe [102], Mn [95], and Co [103-105] tropocoronand complexes. One example is shown in Figure 16.23. The tropocoronand ligands incorporate substituted dimethylaminonaphthalene sulphonate fluorophores. Free ligands exhibit strong fluorescence, which is largely... 

Fig. 13. A pictorial view of the Ni(II) translocation within the heteroditopic ligand 7. The reversible molecular motion is signaled by quenching/revival of the intense anthracene emission, depending on whether the metal center is close to (fluorescence off) or far away from the fluorophore (fluorescence on). This system fits quite well the metaphor of the light switch, as the light emitted by the bulb (the fluorogenic fragment) is switched on/off through a mechanical operation (the pressure of a finger in the everyday life, the controlled displacement of a metal center in the molecular world)...

Fluorescence mission of radiation when a molecule in an excited electronic state returns to the ground state N, P Environment, relative abundance and interactions of fluorophore. Quantitation of proteins and fluorophoric compounds. Ligand binding studies. 

Applications of fluorescence spectroscopy include ligand binding, probing of environment and measurement of distance between fluorophores. Fluorescence is very sensitive to the environment and the various parameters (e.g. ( )f and x) that are affected,... 

Solvent polarity and the local environment have profound effects on the emission spectra of polar fluorophores. These effects are the origin of the Stokes shift, which is one of the earliest observations in fluorescence. Emission spectra are easily measured, and as a result, there are num ous publications on emission spectra of fluoropho-res in different solvents and when bound to proteins, membranes, and nucleic acids. One common use of solvent effects is to determine the polarity of the probe binding site on the macromolecule. This is accomplished by comparison of the emission Spectra and/or quantum yields of the fluorophore when it is bound to the macromolecule and when it is dissolved in solvents of different polarity. However, there are many additional instances where solvent effects are used. Suppose a fluorescent ligand binds to a protein. Binding is usually accompanied by a spectral shift due to the different environment for the bound ligand. Alternatively, the ligand may induce a spectral shift in the intrinsic or extrinsic protein fluorescence. Additionally, fluorophores often display spectral shifts when they bind to membranes. 

Hanrahan reported in 2013 the synthesis and the pharmacological studies of a series of fluorescent ligands containing different-sized linkers and fluorophores based around (5)- and (J )-4-ACPBPA (Scheme 19) as selective GAB Ac... 

Previously reported selective potent GABAc antagonists (S)- and (/ )-4-ACPBPA were used for the design of the fluorescent GABAc antagonists. To introduce molecular flexibility into the conjugated fluorescent ligand, Hanrahan et al. chose a linker size that varied from zero to ten carbon atoms and three different fluorophores [NMA (AT-methylanthranilic acid), 4,4-difluoro-4-bora-3a,4a-diaza-s-indacene (BODIPY) and 7-nitrobenz-2-oxa-l,3-diazol-4-yl chloride... 

We have also used a non-radiometric-binding approach based on fluorescence polarisation [29], where a fluorescent label is used in place of a radiolabel. As the fluorescently tagged oxytocin binds to the receptor, its rotational velocity is reduced and the polarisation of the fluorophore increases. The displacement of the ligand may be measured by a decrease in polarisation. 

Brown, M., Edmonds, T., Miller, J. and Seare, N. (1993). Use of nile red as a long-wavelength fluorophore in dual-probe studies of ligand-protein interactions. J. Fluorescence 3, 129-130. 

Oligonucleotide probes may be labeled with small fluorescent molecules for detection of hybridization by luminescence. Fluorescent probes are widely used in assay systems involving bio-specific interactions (Chapter 9). Receptors for ligands may be localized in tissues or cells by modification of the ligand with the appropriate fluorophore. Targeted molecules may be... 

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