title: Purification of five creatine kinase-MM variants from human heart and skeletal muscle.
abstract: Variants of creatine kinase-MM (variant of ATP:creatine N-phosphotransferase, EC 2.7.3.2), present in human heart and skeletal muscle, have been purified to homogeneity using DEAE-Sepharose column chromatography and column chromatofocusing techniques. Creatine kinase-MM I-IV were present in both heart and skeletal muscle, while MM-V was found only in heart. The number, ratio and elution profile of the variants during chromatofocusing remained identical even when they were purified in the presence of proteinase inhibitors. MM-I-V, on chromatofocusing, were eluted at pH 8.3, 7.9, 7.6, 7.2 and 6.8, respectively. Isoelectric focusing revealed the pI of MM-I-V to be 7.2, 6.9, 6.7, 6.4 and 6.2. Sodium dodecyl sulfate (SDS) polyacrylamide gel electrophoresis showed a doublet pattern for creatine kinase-MM variants III-V. However, polyacrylamide gel electrophoresis without SDS indicated homogeneity because each variant showed a single band. The doublet pattern observed in the presence of SDS may reflect the presence of two subunits of slightly different mass.
mesh_terms: D003402:Creatine Kinase / Q000302:isolation & purification*; D006801:Humans; D007526:Isoelectric Point; D007527:Isoenzymes / Q000302:isolation & purification; D046911:Macromolecular Substances; D009132:Muscles / Q000201:enzymology*; D009206:Myocardium / Q000201:enzymology*
chemical_list: D007527:Isoenzymes; D046911:Macromolecular Substances; D003402:Creatine Kinase