Phosphofructokinase from the epithelial cells of rat small intestine. Comparison of regulatory properties with those of skeletal muscle, liver and brain phosphofructokinase.
The regulatory properties of phosphofructokinase from rat mucosa, liver, brain and muscle were investigated. Mucosal phosphofructokinase displayed cooperativity with respect to fructose 6-phosphate at pH 7.0 and so did the muscle, brain and liver isoenzymes. All these four isoenzymes were inhibited by ATP, the mucosal isoenzyme being the least inhibited. They were also inhibited by citrate and creatine phosphate. AMP, ADP, glucose 1,6-diphosphate, fructose 2,6-bisphosphate and inorganic phosphate were all strong activators for the mucosal, brain, liver and muscle phosphofructokinase, but the mucosal isoenzyme was found to be more activated than the others, accounting for the higher rates of glycolysis observed in mucosa. The results suggest that mucosal phosphofructokinase is unique and different from all the other isoenzymes.
D000818:Animals; D001921:Brain / Q000201:enzymology*; D004789:Enzyme Activation; D007421:Intestine, Small / Q000201:enzymology*; D007700:Kinetics; D008099:Liver / Q000201:enzymology*; D008297:Male; D009132:Muscles / Q000201:enzymology*; D009928:Organ Specificity; D010732:Phosphofructokinase-1 / Q000037:antagonists & inhibitors / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains
D010732:Phosphofructokinase-1