Studies on Liver Aldolases in Hereditary Fructose Intolerance

Abstract

In hereditary fructose intolerance (HFI) the greatest part of the fructose diphosphate aldolase activity of liver is due not only to aldolase A (muscle type) but also to aldolase C (brain type). A residual aldolase B activity was found with lowered affinity for its more specific substrate, fructose-1-phosphate. This kinetic abnormality is intrinsically due to aldolase B, since it persists after precipitation by the specific antiserum against aldolase C. In all cases tested by the Ouchterlony technique, we have found a precipitation line between HFI liver extracts and antiserum against aldolase B. This line showed a reaction of partial identity with the precipitation line obtained against normal liver aldolase. These findings provide evidence for a structural mutation of aldolase B in all cases of HFI.