Fluorophores families

The amine-reactive 5-(dimethylamino)naphthalene-l-sulfonyl (dansyl) chloride 28 [80] and related fluorophores [81, 82], as well as the 5-((2 aminoethyl)amino) naphthalene-1-sulfonic acid (EDANS) 29, are included in the naphthalene fluorophore family. Derivatives of the latter, such as compound 30, exhibit a Lm.ix/ Lem 336/520 nm, molar absorptivity (e) of 6.1 x 103 M-1 cm-1, and a fluorescent quantum yield of 0.27 in water [83], The use of EDANS is particularly interesting in FRET experiments [84, 85]. Furthermore, 4-amino-3,6-disulfonylnaphthalimides (e.g., Lucifer yellow 31), associated to a longer absorption (Lmax 428 nm) [86] are suitable polar tracers [87]. 

Antibody molecules can be labeled with any one of more than a dozen different fluorescent probes currently available from commercial sources. Each probe option has its own characteristic spectral signals of excitation (or absorption) and emission (or fluorescence). Many derivatives of these fluorescent probes possess reactive functionalities convenient for covalently linking to antibodies and other molecules. Each of the main fluorophore families contains at least a few different choices in coupling chemistry to direct the modification reaction to selected functional groups on the molecule to be labeled. These choices include amine-reactive, sulfhydryl-reactive, and carbonyl-reactive. Examples of some of the more popular varieties of fluorescent probes can be found in Chapter 9. 

Morris DL, Ledden DJ, Boguslaski RC (1987) Dry-phase technology for immunoassays. J Clin Lab Anal 1 243-249 Moss AJ, Dalrymple GV, Boyd CM (1976) Practical Radioimmunoassay. The C.V. Mosby Company, St. Louis Odell WD, Franchimont P (1983) Principles of Competitive Protein-Binding Assays. John Wiley and Sons, New York Read B (2001) Long-distance runners of the fluorophore family. Amer Biotechnol Lab 44... 

Benzo[i7]thiophen-3-yl)pyrrole (37) was reacted sequentially with mesityl aldehyde, DDQ and Bp3-OEt2 to afford 4,4-difluoro-3,5-di(benzo [ 7]thiophen-3-yl)-8-mesityl-4-bora-3a,4a-diaza-s-indacene (156) (Equation (46)), a representative of the novel BODIPY fluorophore family in 34% overall yield (09CEJ5823). 

Photophysics and Spectroscopy of Fluorophores in the Green Fluorescent Protein Family. 347... 

Yang Y, Lowry M, Xu X, Escobedo JO, Sibrian-Vazquez M, Wong L, Schowalter CM, Jensen TJ, Fronczek FR, Warner IM, Strongin RM (2008) Seminaphthofluorones are a family of water-soluble, low molecular weight, NIR-emitting fluorophores. Proc Natl Acad Sci USA 105 8829-8834... 

Merola F, Levy B, Demachy I, Pasquier H (2010) Photophysics and Spectroscopy of Fluorophores in the Green Fluorescent Protein Family. In Demchenko AP (ed) Advanced Fluorescence Reporters in Chemistry and Biology I. Springer Ser Fluoresc 8 347-383... 

Proteases are one of the largest families of enzymes and are involved in a multitude of vital processes. Due to their biological relevance and diversity, multiple fluorescent reporters monitoring their activity have been designed and successfully applied in vitro and in vivo [112-114]. Standard small molecule FRET probes for proteases consist of an amino acid sequence flanked by a FRET pair, consisting of two fluorophores or one fluorophore and a quencher molecule. Upon cleavage of the peptide sequence, the emission of the donor fluorophore is dequenched and the intensity increases whereas the emission of the acceptor decreases and vanishes more or less completely in those cases where the acceptor is fluorescent (see Fig. 6.11). 

Eukaryotic cells utilize an efficient transport system that delivers macromolecules fast and secure to their destination. In the case of the small GTP binding proteins of the Ras family the modified C-terminus seems to be sufficient for addressing the polypeptide to its target membrane (in the case of Ras itself the plasma membrane). Lipopeptides with the C-terminal structure of N-Ras (either a pen-tamer with a C-terminal carboxymethylation and farnesylation or a heptapeptide with a palmitoyl thioester in addition) and a N-terminal 7-nitrobenz-2-oxa-l,3-diazolyl (NBD) fluorophore were microin-jected into NIH3T3 fibroblast cells and the distribution of the fluorophore was monitored by confocal laser fluorescence microscopy. Enrichment of the protein in the plasma membrane was efficient only for peptides with two hydrophobic modification sites, while the farnesylated but not palmitoylated peptide was distributed in the cytosol.1121... 

In this respect, Johansson 1 reported that ro is the same (within experimental accuracy) for fluorophores belonging to the same family, e.g. perylene and per-ylenyl compounds (0.369 + 0.002), or xanthene derivatives such as rhodamine... 

In the ferrioxamine family, two approaches were followed one, based on modifying the amine at the end of the extended tail in the natural ferrioxamine B with an appropriate fluorophore the second, substituting biomimetic analogs 146-155 on either their amino or carboxy termini, to assess their chemical and biological differences. Both approaches were followed and two classes of compounds were prepared with various fluorescent tags. 

Colistin is a linear-ring peptide antibiotic. Its main components are colistin A and colistin B. It is a member of the polymyxin family of antibiotics that is stable in dry form and in water solution. The sulfate salt of colistin, which is usually administered as feed additive, is soluble in water, slightly soluble in methanol, and practically insoluble in acetone and ether. Colistin components do not have any specific fluorophore and UV chromophore, so detection by liquid chromatography at residue levels of interest is difficult without including a suitable derivatization step in the analytical method. 

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