Peptides with thiol donor functions

Complexes of Peptides with Thiol Donor Functions. 291... 

N-acetyl-L-cysteine and N-acetyl-D-penicillamine are the simplest ligands containing the thiolate and amide donor functions in the same molecule. For understanding the coordination chemistry of L-cysteine and its peptide derivatives, it is important to take into account that the thiol group can form a five-membered chelate with the amide-N and a six-membered one with the carboxylate-O donor atoms. All studies rule out a cadmium(ll)-induced amide coordination in these complexes, therefore the formation of the (S,0) chelate is the governing factor during complex formation with N-acetyl-L-cysteine. The equilibrium data have... 

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