NMR studies of ligand carboxylate group interactions with arginine residues in complexes of Lactobacillus casei dihydrofolate reductase with substrates and substrate analogues

Ligand carboxylate group interactions with arginine residues in complexes of Lactobacillus casei dihydrofolate reductase with substrate analogues and substrates have been studied using NMR. The study was to investigate the structures and dynamics of the Arg 57 guanidino interactions with ligand carboxylate groups in complexes of DHFR with the substrate folate and its fragment, PABG. The carboxylate group binds to the enzyme in a way like that in a parent molecule such as methotrexate or folate.