Tissue distribution, immunoreactivity, and physical properties of 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase
| Autor: | M R el-Maghrabi, P J Heil, C E Cobb, J J Correia, S J Pilkis, T M Pate |
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| Jazyk: | angličtina |
| Rok vydání: | 1986 |
| Předmět: |
Male
Phosphofructokinase-2 Biology Cross Reactions Kidney Substrate Specificity Antibody Specificity Testis medicine Animals Phosphofructokinase 2 Kinase activity Phosphorylation Stokes radius chemistry.chemical_classification Antiserum Multidisciplinary Kinase Myocardium Phosphotransferases Skeletal muscle Phosphoric Monoester Hydrolases Rats Isoenzymes Molecular Weight Enzyme medicine.anatomical_structure Biochemistry chemistry Liver Research Article |
| Popis: | 6-Phosphofructo-2-kinase (EC 2.7.1.105) and fructose-2,6-bisphosphatase (EC 3.1.3.46) activities were determined in various rat tissues, the latter by using a method based on the formation of a phosphorylated enzyme intermediate during the course of catalysis. Both activities from liver, skeletal muscle, lung, kidney, and testis copurified during polyethylene glycol fractionation, anion-exchange and blue Sepharose chromatography, and gel filtration. The Stokes radius of these enzymes and of the liver bifunctional enzyme was 45 A. Extrahepatic tissues had only 10% or less of the kinase activity found in liver. The results indicate that a liver-type bifunctional enzyme is present in most extrahepatic tissues but that it is minimally expressed. However, the ratio of kinase to bisphosphatase activity in most extrahepatic tissues was 4- to 6-fold higher than in liver, whereas heart 6-phosphofructo-2-kinase had no associated bisphosphatase activity, although its Stokes radius was also 45 A. The heart enzyme was not precipitated by an antiserum to the liver enzyme, whereas only a fraction of the kidney and testis activities was precipitated by this antiserum. The data support the existence of a distinct form of extrahepatic 6-phosphofructo-2-kinase, most readily demonstrated in heart, which may not be bifunctional. |
| Databáze: | OpenAIRE |
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