Abstract
The possibility of using selectively incorporated (19)F nuclei for NMR spectroscopic studies has retrieved increasing interest in recent years. The high gyromagnetic ratio of (19)F and its absence in native biomolecular systems make this nucleus an interesting alternative to standard (1)H NMR spectroscopy. Here we show how we can attach a label, carrying a (19)F atom, to protein tyrosines, through the use of a specific three component Mannich-type reaction. To validate the efficacy and the specificity of the approach, we tested it on two selected systems with the aid of ESI MS measurements.