La. Luck et C. Johnson, Fluorescence and F-19 NMR evidence that phenylalanine, 3-L-fluorophenylalanine and 4-L-fluorophenylalanine bind to the L-leucine specific receptor ofEscherichia coli, PROTEIN SCI, 9(12), 2000, pp. 2573-2576
The binding capacity of the L-leucine receptor from Escherichia coli was me
asured with L-phenylalanine and 4-fluoro-L-phenylalanine as substrates by f
luorescence. The apparent dissociation constants (K-D) for L-leucine, L-phe
nylalanine, and 4-fluoro-L-phenylalanine are 0.40. 0.18. and 0.26 respectiv
ely. F-19 NMR data show protein-induced shifts for the 4-fluoro-L-phenylala
nine peak and 3-fluoro-L-phenylalanine when receptor is present. Evidence p
oints to the binding of only the L-isomers of these fluorine analogs.