Lyases, zinc enzyme reactions

The normal zinc content of the body amounts to 20-30 mmol (1.3-2.0 g). The daily dietary requirement is 10-15 mg. In the blood, zinc is bound to tt2-macro-globulin, albumin or amino acids, and a small amount is also bound to transferrin. Zinc is crucial to a variety of enzyme reactions. This applies especially to the liver. More and more attention has therefore been paid to the role of zinc in liver disease in recent years. Six enzyme groups (hydrolases, isomerases, ligases, lyases, oxidore-ductases and transferases) with a total of 35 zinc metal-loenzymes are listed. (98) Almost 200 enzyme reactions in the body are zinc-dependent ... 

Zinc is an essential trace element. More than 300 enzymes that require zinc ions for activity are known. Most catalyze hydrolysis reactions, but zinc-containing representatives of aU enzyme classes are known, such as, for instance, alcohol dehydrogenase (an oxidoreductase), famesyl-Zgeranyl transferase (a transferase), -lactamase (a hydrolase), carbonic anhydrase (a lyase) and phosphomannose isomerase. 

More than 300 reactions are catalyzed by zinc-containing enzymes [82]. Zinc can be found with insulin, in the reproductive tract, in the DNA-binding proteins, and in oxidoreductases, transferases, lyases, isomerases, and ligases. 

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