A key player in the process appears to be an enzyme in the liver known as fructokinase
, which metabolizes fructose so rapidly that it causes ATP depletion.
activity mediates dehydration-induced renal injury.
Immunodetection of glucokinase (GCK), fructokinase
(FK), phosphofructokinase-2 (PFK2), and ACTINB was performed with liver homogenates from each experimental group.
The mechanism is not fully understood but it is known that fructose-1-phosphate (a metabolite formed in the liver by fructokinase
that phosphorylates quickly fructose, using a molecule of ATP), has the ability to dissociate glucokinase from glucokinase regulatory protein (GKRP).
High-fat and high-sucrose (western) diet induces steatohepatitis that is dependent on fructokinase
Fructose is metabolized by fructokinase
, an enzyme that has two isoforms: fructokinase
A and fructokinase
The team got similar results when they gave the glucose water to mice engineered to lack fructokinase
, an enzyme that trips the chain reaction by which fructose is metabolized.
This strong anti-inflammatory activity of atorvastatin could be attributed to two factors: the well-known inhibition of NFkB activity by atorvastatin and the reduced liver metabolism of fructose, resulting from atorvastatin-mediated decreased expression of fructokinase
, thus alleviating hepatic metabolic stress and the production of pro-inflammatory products.
When fructose is ingested, it is acted upon by the enzyme fructokinase
to produce fructose-1-phosphate, consuming in the process one molecule of ATP and generating ADP and inorganic phosphate ([P.
The activities of ATP-dependent fructokinase
, UTP-dependent fructokinase
, glucokinase, and sucrose synthase were measured in dialyzed extracts, with dialysis conducted overnight in extraction buffer at 4 [degrees] C.
Of 53 enzyme assays tried, the following gave scorable results (designation of presumptive loci in parentheses): Alkaline phosphatase (Alkph-1 and Alkph-2), Esterases (Est-1 and Est-2), N-Acetyl-[Beta]-glucosaminase ([Beta]Ga), Fructokinase
(Fk), Fumarate dehydrogenase (Fum), Glutamate-oxaloacetate transaminase (Got), Glutamic dehydrogenase (Glutdh), [Alpha]-Glycerophosphate dehydrogenase ([Alpha]Glyphdh), Mannose-6-phosphate isomerase (M6pi), NAD+ dependent Malate dehydrogenase (Mdh-1 and Mdh-2), L-Leucyl-L-Tyrosine peptidase (Peplt), Phosphoglucose isomerase (Pgi), Phosphoglucomutase (Pgm), Triosephosphate isomerase (Tpi).
Ketohexokinase or hepatic fructokinase
catalyzes the first step in the metabolism of dietary fructose to produce energy, converting fructose into fructose-1-phosphate; malfunction of this enzyme causes diabetes mellitus (Hayward et al.