Enzymes manganese requirements

Pyruvate Carboxylase. This enzyme has manganese firmly in its structure and acts together with phosphoenol pyruvate (PEP) carboxykinase, an enzyme that is activated by manganese ions. These enzymes are required to catalyze the formation of PEP from pyruvate, a key reaction in the hepatic synthesis of glucose. 

Pyruvate may enter the Krebs cycle by a pathway different from that involving the formation of acetyl-CoA. Indeed, the keto acid can be converted to a dicarboxylic acid by at least two different biochemical processes. One of them involves the carboxylation of pyruvic acid leading to the formation of oxaloacetic acid. The actual substrate in that reaction is not pyruvic acid, but phosphoenolpyruvic acid. The enzyme involved requires manganese, and IDP acts as the phosphorus acceptor. The reaction is coupled with the pyrophosphate transfer (catalyzed by nucleoside diphosphokinase) from ITP to ADP. 

In both C. acremonium and S. clavuligerus deacetoxycephalosporin C is oxidised to deacetylcephalosporin C (301). Liersch et al. (301) observed that cell-free extracts of C. acremonium could convert, deacetoxycephalosporin C to cephalosporin C and that the enzymic system required molecular oxygen, manganese ions and NADH (or NADPH) as co-factors. From this they concluded that an oxygenase was involved and postulated (301) as the intermediate in cephalosporin C production. Stevens etal. 

Metabolic Functions. Manganese is essential for normal body stmcture, reproduction, normal functioning of the central nervous system, and activation of numerous enzymes (126). Synthesis of the mucopolysaccharide chondroitin sulfate involves a series of reactions where manganese is required in at least five steps (127). These reactions are responsible for formation of polysaccharides and linkage between the polysaccharide and proteins that form... 

Some enzymes require metal ions - such as cobalt, manganese or zinc - for their activity if these are removed by the ionic liquid by complexation, enzyme inactivation may occur. 

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