Covalent tagging

Small fractions of a similar type of merocyanine dye moieties (Me) were also covalently tagged onto poly(sodium 2-acrylamido-2-methylpropanesulfonate) (AMc-3, 4) and poly[(3-(methacrylamino)propyl)trimethylammonium chloride] (QMc-1, 5) [49], The observed pKobs value of 10.92 for AMc-3 was higher than that for the neutral reference (NMc-3, 6) by 2.24 pH units. By contrast, the... 

Chattopadhaya and co-workers [162] recently reported another approach used to avoid some of the drawbacks associated with the use of FPs. The authors described a small molecule-based procedure that makes use of the unique reactivity between the cysteine residue at the N-terminus of a target protein and cell-permeable, thioester-based small molecule probes resulting in site-specific, covalent tagging of proteins. 

Isotope-Coded Affinity and Covalent Tagging Methods... 

Figure 1. The bioorthogonal chemical reporter strategy. First, unnatural monosaccharides are metabolically incorporated into glycoconjugates. Next, the unnatural functionality (black square) is covalently tagged using appropriately derivatized reagents (white square).

Covalent Tagging of Chemical Reporters Using Bioorthogonal... 

Leitner, A. Linder, W. Functional probing of arginine residues in proteins using mass spectrometry and an arginine-specific covalent tagging concept. Anal. Chem. 2005, 77, 4481 88. 

Apart from the interaction between catalyst and substrate, halogen bonds can also be used in other aspects of organic synthesis. For example, Legros et al. employed a perfluorinated XB donor to facilitate the recycling of the actual organocatalyst of the reaction. This application was based on the concept to non-covalently tag the catalyst with perfluorinated alkane chains ( pony tailing ) [127], so that the resulting fluorophUic complex readily precipitates from some... 

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