Intracellular distribution of NADP-linked isocitrate dehydrogenase, fumarase and citrate synthase in bovine heart muscle.
By fractional extraction of minced bovine heart muscle with iso-osmotic sucrose and phosphate buffer solutions, it is shown that less than 4% of the total citrate synthase in the tissue is in the cytosol. Using citrate synthase as a marker for broken mitochondria, two methods of fractionation of 750 x g supernatants from homogenates of bovine heart muscle show that 10% of the total fumarase and NADP-linked isocitrate dehydrogenase activities are present in the cytoplasm. Homogenates prepared by sonication and osmotic shock and by sand-grinding gave closely similar results as regards enzyme distributions and extent of mitochondrial breakage. The results are compared with those reported for other tissues.
D000818:Animals; D002417:Cattle; D002451:Cell Compartmentation; D002458:Cell Fractionation / Q000379:methods; D002950:Citrate (si)-Synthase / Q000378:metabolism*; D003593:Cytoplasm / Q000201:enzymology; D003600:Cytosol / Q000201:enzymology; D005649:Fumarate Hydratase / Q000378:metabolism*; D007521:Isocitrate Dehydrogenase / Q000378:metabolism*; D008929:Mitochondria, Heart / Q000201:enzymology; D009206:Myocardium / Q000201:enzymology*; D009249:NADP / Q000378:metabolism; D007652:Oxo-Acid-Lyases / Q000378:metabolism*
D009249:NADP; D007521:Isocitrate Dehydrogenase; D002950:Citrate (si)-Synthase; D007652:Oxo-Acid-Lyases; D005649:Fumarate Hydratase