2+ ion in the active site, which is required for its enzyme activity. We have analyzed interaction between TLN and its inhibitors by thermodynamic methods. We have revealed that a series of stereo-isomeric inhibitors, benzyloxycabonyl-amino acids (hereafter Z-L(D)-amino acid), are ideal compounds to analyze thermodynamics of TLN-inhibitor interaction. To date, thermodynamic parameters for the interaction between TLN and Z-L(D)-amino acid have been experimentally determined. In order to improve and establish the method to predict the binding thermodynamics, computer simulation work has also been carried out. To validate these results, we have tried to determine the crystal structures of TLN in complex with various inhibitors, Z-L(or D)-amino acid.