Page 11 - BIOCHEMISTRY II

Phosphofructokinase (PFK-1) as a
regulator of glycolysis

fructose-6-phosphate PFK-1
fructose-1,6-bisphosphate

PFK allosterically inhibited by:

•High ATP lower affinity for

fructose-6-phosphate by binding to a

regulatory site distinct from catalytic

site.

•High H+ reduced activity to prevent

excessive lactic acid formation and drop in

blood pH (acidosis).

•Citrate prevents glycolysis by

accumulation of this citric acid cycle

intermediate to signal ample biosynthetic

precursors and availability of fatty acids

or ketone bodies for oxidation. 10