title: Purification and properties of pyruvate kinase from the hepatopancreas of Carcinus maenas.
abstract: Pyruvatekinase from the hepatopancreas of the common shore crab, Carcinus maenas, was purified to a specific activity of 240 units/mg of protein in the assay conditions described. 2. In one method of purification the enzymic activity could be resolved into two fractions after chromatography on DEAE-cellulose. Fructose 1, 6-diphosphate was able to effect the conversion of one form (peak 1) into the second (peak 2). 3. In the presence of a saturating concentration of fructose 1, 6-diphosphate both forms of the enzyme were kinetically similar. 4. Polyacrylamide-gel electrophoresis of the enzyme 1 day after preparation showed a single protein band. On storage at least three protein bands became visible, all of which were associated with pyruvate kinase activity. 5. Chromatography of the enzyme on Sephadex G-200 indicated a mol.wt. of 247000, but in the presence of fructose 1, 6-diphosphate the elution volume of the enzyme increased corresponding to a mol.wt. of 193000. 6 Dissociation of the enzyme in sodium dodecyl sulphate and 2-mercaptoethanol followed by polyacrylamide-gel electrophoresis produced one major protein band with a mol.wt. of 55000.
mesh_terms: D000818:Animals; D002021:Buffers; D002848:Chromatography, DEAE-Cellulose; D002850:Chromatography, Gel; D004591:Electrophoresis, Polyacrylamide Gel; D008099:Liver / Q000201:enzymology*; D008623:Mercaptoethanol; D008970:Molecular Weight; D010179:Pancreas / Q000201:enzymology*; D011770:Pyruvate Kinase / Q000302:isolation & purification*; D012967:Sodium Dodecyl Sulfate
chemical_list: D002021:Buffers; D012967:Sodium Dodecyl Sulfate; D008623:Mercaptoethanol; D011770:Pyruvate Kinase