Dinuclear Zinc Hydrolase Mimics

Numerous research groups have reported Zn(II)Zn(Il) hydrolase mimics [5, 24, 28-31, 33-39]. The strategies for ligand and complex design are diverse and have been recently reviewed [5, 32,40]. Thus, only a brief overview of different ligands 

The separation of the two zinc centers in the biomimetics has been shown to be important. Meyer et al. correlated the hydrolytic activity of dizinc phosphodiesterase models (Table 4.1, Fig. 4.2, Lg and Lp) with their Zn - Zn distances [38]. Here, the length of the ligand side chains determines the Zn -Zn separation. The distance of the two Zn(ll) ions in the complex with Lq is rather short with 3.4 A, while the metal ions are separated by more than 4.1 A with ligand Lp. The authors proposed that the separation of the Zn(II) centers is significant in terms of the ability of the metal complexes to efficiently catalyze the hydrolysis of the substrate, in this case BPNPP [38]. The kcat for the Zn(II) complex [Zn2(LpH i)(Me0H)(0H)](C104)2, where the Zn(II) ions have a greater 

Complex kcat [S ] KM[mM] Substrate pFl opti-mum T[K] Solvent system Kinetic pK Potentio-metric pK  

---