Fructose biphosphate phosphatase

Cellular levels of fructose-2,6-biphosphate, the positive effector of PFK I, are increased when blood insulin levels are high because PFK II is active as a result of a suppression of fructose-2,6-biphosphate phosphatase (dephosphorylation) and activation (dephosphorylation) of PFK II. 

In nature, many enzymes that hydrolyze phosphate monoesters are activated by two or more metal ions. They include alkaline phosphatase [79], purple acid phosphatase [80], inositol monophosphatase [81], and D-fructose 1,6-biphosphate 1-phosphatase [82]. The active sites of protein serine and threonine phosphatases also consist of dinuclear... 

Figure 6.18 Active site ofD-fructose 1,6-biphosphate 1-phosphatase.

The structure of D-fructose 1,6-biphosphate 1-phosphatase has been reported [82]. Proposedly, the two metal centers at the active site of the enzyme are bridged by the substrate phosphate monoester, and a metal hydroxide is involved in the hydrolysis (Figure 6.18). 

Fructose-2,6-biphosphate levels Stimulation PDH phosphatase Stimulation... 

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