title: Purification, crystallization and properties of triosephosphate isomerase from human skeletal muscle.
abstract: 1. Triosephosphate isomerase (D-glyceraldehyde-3-phosphate ketoisomerase, EC 5.3.1.1) from human skeletal muscle was purified to homogeneity and crystallized. The crystalline enzyme preparation was resolved on polyacrylamide-gel electrophoresis into three isoenzymes. 2. The molecular weight of the enzyme estimated by gel filtration method was found to be 57,400 +/- 3000. Molecular weight determination under dissociation conditions indicated a dimeric subunit structure of the enzyme. 3. The apparent Km for D-glyceraldehyde-3-phosphate as substrate is 0.34 mM, and for dihydroxyacetone phosphate, 0.61 mM. Vmax of the reaction is, respectively, 7200 and 660 units/mg protein at 25 degrees C and pH 7.5. 4. Molecular and kinetic properties of triosephosphate isomerase from human skeletal muscle are very similar to those of rabbit muscle enzyme.
mesh_terms: D002238:Carbohydrate Epimerases / Q000302:isolation & purification* / Q000378:metabolism*; D002845:Chromatography / Q000379:methods; D003460:Crystallization; D006358:Hot Temperature; D006801:Humans; D007700:Kinetics; D009132:Muscles / Q000201:enzymology*; D011489:Protein Denaturation; D014305:Triose-Phosphate Isomerase / Q000302:isolation & purification* / Q000378:metabolism*
chemical_list: D002238:Carbohydrate Epimerases; D014305:Triose-Phosphate Isomerase