Abstract
We present an economic and straightforward method to introduce (13)C-(19)F spin systems into the deuterated aromatic side chains of phenylalanine as reporters for various protein NMR applications. The method is based on the synthesis of [4-(13)C, 2,3,5,6-(2)H(4)] 4-fluorophenylalanine from the commercially available isotope sources [2-(13)C] acetone and deuterium oxide. This compound is readily metabolized by standard Escherichia coli overexpression in a glyphosate-containing minimal medium, which results in high incorporation rates in the corresponding target proteins.