Clustering of sequential enzymes in the glycolytic pathway and the citric acid cycle.
In recent years, evidence has been accumulating that metabolic pathways are organized in vivo as multienzyme clusters. Affinity electrophoresis proves to be an attractive in vitro method to further evidence specific associations between purified consecutive enzymes from the glycolytic pathway on the one hand, and from the citric acid cycle on the other hand. Our results support the hypothesis of cluster formation between the glycolytic enzymes aldolase, glyceraldehydephosphate dehydrogenase, and triosephosphate isomerase, and between the cycle enzymes fumarase, malate dehydrogenase, and citrate synthase. A model is presented to explain the possibility of regulation of the citric acid cycle by varying enzyme-enzyme associations between the latter three enzymes, in response to changing local intramitochondrial ATP/ADP ratios.
Laboratorium voor Chemie der Proteïnen, Vrije Universiteit Brussel, Sint-Genesius-Rode, Belgium.
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S
Beeckmans
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E
Van Driessche
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L
Kanarek
D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D002417:Cattle; D002950:Citrate (si)-Synthase / Q000378:metabolism; D002952:Citric Acid Cycle; D005634:Fructose-Bisphosphate Aldolase / Q000378:metabolism; D005649:Fumarate Hydratase / Q000378:metabolism; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases / Q000378:metabolism; D006019:Glycolysis; D008291:Malate Dehydrogenase / Q000378:metabolism; D008928:Mitochondria / Q000201:enzymology / Q000378:metabolism; D008954:Models, Biological; D009097:Multienzyme Complexes / Q000378:metabolism*; D011817:Rabbits; D013552:Swine; D014305:Triose-Phosphate Isomerase / Q000378:metabolism
D009097:Multienzyme Complexes; D000255:Adenosine Triphosphate; D008291:Malate Dehydrogenase; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases; D002950:Citrate (si)-Synthase; D005634:Fructose-Bisphosphate Aldolase; D005649:Fumarate Hydratase; D014305:Triose-Phosphate Isomerase