Metal ions, in enzymes

Metal ions in enzymic catalysis. J. E. Coleman, Prog. Bioorg. Chem., 1971,1,159-344 (503),... 

Before discussing the mechanistic aspects of the PLCSc catalyzed hydrolysis of phospholipids, a brief survey of the manner in which metal ions in enzyme active sites participate in catalysis is warranted. 

Several books and review articles are available dealing with various aspects of metal ion atalysis,4 24,29-32 and the role of metal ions in enzymic catalysis.25"28... 

Metal Ions in Enzyme Catalyzed Phosphoryl Transfer... 

Coenzymes and What They Do (Table 11.5, Structure, Figure 11.25, Figure 11.26) Metal Ions in Enzymes (Figure 11.27)... 

An extreme example of the importance of electrostatic interactions is the solubility of salts which also highlights the role of metal ions in enzymes. The solubility product, K, of a salt is related to the free energy of solution AG by Eqn. 58... 

Provision of an available nucleophile at physiological pH is an important role for the metal ion in the model chemistry, and it is a likely role for the metal ion in enzymes. 

Metal Ions In enzymes using ammonia or amides. Science,... 

Sigel RKO, Pyle AM Alternative roles for metal ions in enzyme catalysis and the implications for ribozyme chemistry. Chem Rev 2007, 107(1) 97-113. 

Dixon, N. E., Gazzola, C., Blakely, R. L., and Zerner, B., 1976, Metal ions in enzymes using ammonia or amides. Science 191 1144. 

Any tentative explanation of the role of metal ions in enzyme action should consider the bond type, its stereochemistry, and its reactivity. Metal ions can act (i) as a link between enzyme and substrate, (ii) by changing the surface charge of the protein, or (iii) by both of these effects. Transition elements produce metal ions of variable valence. Their redox potential can be changed by complex formation. In this way catalysts of graded reactivity are realized in test tube systems and in living cells. The stereochemistry of the complex may contribute to enzyme specificity also. 

---