D-Fructose-1,6-bisphosphate (FBP), a common metabolic sugar, is the precursor of glyceraldehyde 3-phosphate and dihydroxyacetone phosphate in the glycolytic pathway. It may be used as an allosteric activator of enzymes such as pyruvate kinase and NAD+-dependent L-(+)-lactate dehydrogenase, as an inhibitor of acetate kinase and as a substrate to identify and characterize enzymes such as fructose-1,6-bisphosphate aldolase(s) and fructose-1,6-bisphosphatase(s). FBP is studied as a neuroprotective agent in brain injury. Fructose-1,6-biphosphate, along with fructose-2,6-biphosphate, modulates the activity of phosphofructokinase-1 (PFK-1), the rate-limiting step in glycolysis. During glycolysis, aldolase splits Fructose-1,6-biphosphate into dihydroxacetone phosphate (DHAP) and glyceraldehyde phosphate. Fructose-1,6-biphosphate is also an allosteric activator of the M2 isoform of Pyruvate Kinase (PK-M2), the predominant form of pyruvate kinase in cancer cells.
