Abstract: Lanthanide-induced shifts have been measured for ¹H and ¹³C nuclei of L-cy-steine in the presence of eight different lanthanide cations (La, Pr, Nd, Eu,Dy, Ho, Er, Tm).The complex formation shift and the pH dependance of lanthanide-induced shift indicate that L-cysteine is coordinated to lanthanide cations through its ionized carboxylic group.The complex stability constants show that sulfhydryl group is favorable for amino acid coodinating to lanthanide ions. The simulated calculation of the dipolar shift reveals that carboxylic and sulfhydryl groups are in gauche position in the complexes of L-cysteine and carboxylic group is coordinated to lanthanide cations through a single oxygen atom.

Key words: ¹H, ¹³C-NMR spectra, L-cysteine, lanthanide-induced shift