title: Fructose 2,6-bisphosphate as a contaminant of commercially obtained fructose 6-phosphate: effect on PPi:fructose 6-phosphate phosphotransferase.
abstract: Fructose 6-phosphate from several commercial sources was shown to be contaminated with fructose 2,6-bisphosphate. This contaminant was identified by its activation of PPi:fructose 6-phosphate phosphotransferase, extreme acid lability and behaviour on ion-exchange chromatography. The apparent kinetic properties of PPi:fructose 6-phosphate phosphotransferase from castor bean endosperm were considerably altered when contaminated fructose 6-phosphate was used as a substrate. Varying levels of fructose 2,6-bisphosphate in the substrate may account for differences that have been observed in the properties of the above enzyme from several plant sources.
mesh_terms: D002852:Chromatography, Ion Exchange; D004789:Enzyme Activation; D005636:Fructosephosphates / Q000302:isolation & purification*; D025481:Phosphofructokinase-2; D010744:Phosphoric Monoester Hydrolases / Q000302:isolation & purification* / Q000378:metabolism; D010770:Phosphotransferases / Q000378:metabolism*; D010944:Plants / Q000201:enzymology
chemical_list: D005636:Fructosephosphates; C027618:fructose-6-phosphate; D010770:Phosphotransferases; D025481:Phosphofructokinase-2; C022502:pyrophosphate-fructose 6-phosphate 1-phosphotransferase; D010744:Phosphoric Monoester Hydrolases