Phosphofructose kinase

Figure 11-2 Roles of phosphofructose kinase and fructose 1,6-bisphosphatase in the control of the breakdown and storage (—+) of glycogen in muscle. The uptake of glucose from blood and its release from tissues is also illustrated. The allosteric effector fructose 2,6-bisphosphate (Fru-2,6-P2) regulates both phosphofructokinase and fructose 2,6-bisphosphatase. These enzymes are also regulated by AMP if it accumulates. The activity of phosphofructokinase-2 (which synthesizes Fru-2,6-P2) is controlled by a cyclic AMP-dependent kinase and by dephosphorylation by a phosphatase.

The tetrasodium salt of carbonylbisphosphonate was originally synthesized by Quimby et al. [76], using hydrolysis of a tetraalkyl dichloromethylenebisphos-phonate in aqueous NaOH. In aqueous solution, the yellow ketone form reversibly converts to its colorless hydrate at acidic pH [76], a process which can be assessed by a combination of 31P-NMR and uv-visible spectroscopy at pH 7, the ketone predominates [93]. The salt moderately inhibits HIV reverse transcriptase in a p24 assay, whereas the parent methylene compound is inactive [64], displays some activity vs the pyrophosphate-dependent phosphofructose kinase of the parasite T. gondii [94] and has found use as a selective inhibitor of PCNA-independent DNA polymerase 6, allowing its enzyme activity to be distinguished from that of DNA polymerase a [95]. 

Phosphofructose kinase fructose-6-phosphate - fructose-l 6-diphosphate 380,000 EC 2.7.1.11... 

Fig. 16.3. Model for glycolysis. Arrows in one direction indicate almost irreversible reactions. Arrows in both directions indicate reactions almost at equilibrium. Broken lines indicate activation (with encircled plus sign) or inhibition (with encircled minus sign) by metabolites. GLU is glucose, HK is hexokinase, F6P is fructose 6 phosphate, PFK is phosphofructose kinase, FDP is fructose 1,6 bi-phosphate, PEP is phosphoenolpyruvate, PK is pyruvate kinase, PYR is pyruvate, and AK is adenylate kinase and LAC is lactate. Prom [7]...

This enzyme [EC 2.7.1.90] (also known as diphos-phate fructose-6-phosphate 1-phosphotransferase, 6-phosphofructokinase (pyrophosphate), and pyrophosphate-dependent 6-phosphofructose-l-kinase) catalyzes the reaction of pyrophosphate (or, diphosphate) with d-fructose 6-phosphate to produce orthophosphate and d-fructose 1,6-bisphosphate. 

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