title: Pyrophosphate functions as phosphoryl donor with UDP-glucose-treated mammalian phosphofructokinase.
abstract: Phosphofructokinase of rabbit muscle, which is specific for nucleoside triphosphates such as ATP, dissociated and gained the capability to utilize pyrophosphate as phosphoryl donor following incubation with UDP-glucose. The pyrophosphate- and ATP-linked activities of UDP-glucose-treated muscle phosphofructokinase were promoted by a protein species that showed a molecular weight of 80 kDa (vs. 320 kDa for the untreated enzyme). In the presence of citrate, a known inhibitor of PFK, the pyrophosphate-dependent activity elicited by UDP-glucose treatment was activated by fructose-2,6-bisphosphate. On removal of the UDP-glucose by either dialysis or dilution, the treated enzyme reassociated and became ATP-specific. ATP, dithiothreitol, and fructose-2,6-bisphosphate stimulated reassociation. The results suggest that metabolite-mediated catalyst conversion, yielding an enzyme form capable of utilizing both ATP and pyrophosphate, takes place with the phosphofructokinases of animal tissues.
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D002384:Catalysis; D011756:Diphosphates / Q000378:metabolism*; D004789:Enzyme Activation / Q000187:drug effects; D008970:Molecular Weight; D009132:Muscles / Q000201:enzymology; D010732:Phosphofructokinase-1 / Q000378:metabolism*; D010770:Phosphotransferases / Q000378:metabolism; D011817:Rabbits; D014532:Uridine Diphosphate Glucose / Q000494:pharmacology*; D014539:Uridine Diphosphate Sugars / Q000494:pharmacology*
chemical_list: D011756:Diphosphates; D014539:Uridine Diphosphate Sugars; D000255:Adenosine Triphosphate; D010770:Phosphotransferases; D010732:Phosphofructokinase-1; C022502:pyrophosphate-fructose 6-phosphate 1-phosphotransferase; D014532:Uridine Diphosphate Glucose