Regulation of rat-renal cortex phosphofructokinase activity by pH.
The activity of phosphofructokinase purified from rat kidney cortex has been assayed at two different pH values. At pH 7 the enzyme showed cooperativity for the binding of fructose 6-phosphate (Fru-6-P) and a strong allosteric inhibition by ATP. When the assays were done at pH 8 hyperbolic kinetics were observed for both substrates, a smaller inhibition by ATP was observed and the Vmax for ATP and for Fru-6-P was higher than at pH 7. A sequential reaction mechanism was inferred. Results are discussed in terms of the importance of a reduced hexose-phosphate cycling rate during metabolic acidosis induced by exercise.
Sola
M M
MM
Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias, Universidad de Granada, España.
Salto
R
R
Oliver
F J
FJ
Gutiérrez
M
M
Vargas
A M
AM
D000255:Adenosine Triphosphate / Q000378:metabolism; D000494:Allosteric Regulation; D000818:Animals; D005636:Fructosephosphates / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D007672:Kidney Cortex / Q000201:enzymology*; D007700:Kinetics; D008297:Male; D008954:Models, Biological; D010732:Phosphofructokinase-1 / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar
D005636:Fructosephosphates; C027618:fructose-6-phosphate; D000255:Adenosine Triphosphate; D010732:Phosphofructokinase-1