Fluorescent reporter group

Miller reported several monomeric, photolabile CCK agonists and antagonists. The photoreactive residue (L-Bpa) was placed at the N-terminal and a fluorescent reporter group was also linked to it. The CCK receptor in the study was expressed on Chinese hamster ovary-CCKR cells. To identify the labeled domains on the receptor capillary electrophoresis was used with laser induced fluorescence detection. Separate regions were labeled with the two photoprobes, one labeled the first extracellular loop (96-121), while the other probe labeled a fragment in the second extracellular loop (174-195). 

Many fluorescence immunoassays have utilized umbelliferone, a 7-hydroxycoumarin (excitation and emission maxima of 360 nm and 447 nm, respectively), as the fluorescence reporter group. Normal serum, however, exhibits emission maximum at 520 nm and excitation maxima of 330 nm and 440 nm. Even with this overlap between the spectra of umbelliferone and normal serum, umbelliferone has one property that makes it suitable for fluorescence immunoassays conversion of the free hydroxyl group to an ester or a glucoside effectively quenches the fluorescence of umbelliferone, and hydrolysis of the ester or glycoside allows for recovery of fluorescence. It is... 

Extrinsic fluorescence is used whenever the natural fluorescence of a macromolecule is inadequate for accurate fluorescence measurement. In this case, one can attach a fluorescent reporter group by using the reactive isocyanate or isothiocyanate derivatives of fluorescein or rhodamine, two intensely fluorescent molecules. One can covalently also label a protein s a- and e-amino groups with dansyl chloride (/.e., A,A-dimethylaminonaphtha-lenesulfonyl chloride). Another useful reagent is 8-ani-lino-l-naphthalenesulfonic acid (abbreviated ANS). This compound is bound noncovalently by hydrophobic interactions in aqueous solutions, ANS is only very fluorescent, but upon binding within an apolar environment, the quantum yield of ANS becomes about 100 times greater. 

With the aim of preparing photoinduced electron transfer devices or simply to be used as fluorescent reporter groups, the synthesis and utility of pyrene-L-alanine have been reported on several occasions. Regarding the development of charge-transfer devices, it was shown that intramolecular electron transfer occurred in 310- and a-helical peptidic systems, such as 182 and 185, between a pyrene and a dimethylaminophenyl chromophore (Scheme 51).[95 101] The rates depend on the relative orientation of the chromophoric side chains and on the framework conformation. Therefore, the preparation of tailor-made charge-transfer devices with tunable properties can be envisaged. 

Ott, G., Faulhammer, H. G., and Sprinzl, M. (1989). Interaction of elongation factor Tu from Escherichia coli with aminoacyl-tRNA carrying a fluorescent reporter group on the 3 terminus. Eur.J. Biochem. 184, 345-352. 

In particular optical sensing systems belong to this group, which are described in detail in Chapter 27. For example, fluorescent reporter groups are incorporated into the MIP, the properties of which are altered upon analyte binding [14-16]. A very sensitive sensor for a hydrolysis product of the chemical warfare agent Soman has been described based on a polymer-coated fiber optic probe and a luminescent... 

Table 19.2a Variation of aminoacyl-tRNA using T. thermophilus EF-Tu GTP. Asp-tRNA originates from yeast and is fully modified. A minihelix consists of two RNA oligonucleotides derived from aminoacyl arm of tRNA. The number of base pair counted from aminoacyl end is indicated in parentheses. His-TYMV RNA is an aminoacylated tRNA-like structure originating from turnip yellow mosaic virus. AEDANS indicates that the fluorescence reporter group was used as an indicator for the measurements of the interaction with EF-Tu GTP whereas 2 or 3 dA, 3 NH, and oxi/red denote different non-isomerisable aminoacyl-tRNAs [28].

Walder, J. A. BehIke, M. A. Devor, E. J. Huang, L. Visual detection assays for RNase using nucleic acid substrates with RNase-cleavable domain flanked by a fluorescence reporter group and a dark fluorescence quencher. U.S. Pat. Appl. Publ. US 2004137479, 2004 Chem. Abstr. 2004, 141, 119302. 

---