FBP2 (Fructose-1,6-bisphosphatase isozyme 2) is a 339 amino acid protein. FBP2 belongs to the FBPase class 1 family. The hydrolysis of fructose-1,6-bisphosphate to fructose-6-phosphate is a key reaction of carbohydrate metabolism. The enzyme that catalyzes this reaction appears to be present in all forms of living organisms. FBPase is encoded by two genes, FBP1 and FBP2, which express the liver and muscle isoforms, respectively. FBPase is regulated by AMP inhibition in most species. Inhibition of FBPase by AMP affects the turnover of bound substrate and not its affinity for substrate.