Presence of enolase in the M-band of skeletal muscle and possible indirect interaction with the cytosolic muscle isoform of creatine kinase
| Autor: | Martine Arrio-Dupont, Georges Foucault, Angélica Keller, Monique Vacher, Tatyana Merkulova |
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| Rok vydání: | 1999 |
| Předmět: |
Gene isoform
Male Enolase Blotting Western Muscle Fibers Skeletal Muscle Proteins Biochemistry Sarcomere Cytosol Western blot Myofibrils medicine Animals Electrophoresis Gel Two-Dimensional Fluorescent Antibody Technique Indirect Molecular Biology Creatine Kinase Psoas Muscles Gel electrophoresis biology medicine.diagnostic_test Skeletal muscle Cell Biology Molecular biology Enzyme Activation Isoenzymes medicine.anatomical_structure Cross-Linking Reagents Phosphopyruvate Hydratase biology.protein Creatine kinase Rabbits Myofibril Dimerization Protein Binding Research Article |
| Zdroj: | The Biochemical journal. 338 |
| ISSN: | 0264-6021 |
| Popis: | Glycerol-skinned skeletal muscle fibres retain the defined sarcomeric structure of the myofibrils. We show here that a small fraction of two enzymes important for energy metabolism, the cytosolic muscle isoform of creatine kinase (EC 2.7.3.2), MM-creatine kinase (MM-CK), and enolase (EC 4.2.1.11), remains bound to skinned fibres. CK is slowly exchangeable, whereas enolase is firmly bound. Two-dimensional gel electrophoresis followed by Western blot analyses demonstrates that both α (ubiquitous) and β (muscle-specific) subunits of enolase are present in these preparations. Enolase and CK were co-localized at the M-band of the sarcomeres, as observed by indirect immunofluorescence and confocal microscopy. Cross-linking experiments were performed on skinned fibres with three bifunctional succinimidyl esters of different lengths and yielded a protein complex of 150 kDa that reacted with antibodies directed against either M-CK or β-enolase. The cross-linking efficiency was greatest for the longest reagent and zero for the shortest one. The length of the cross-linker giving a covalent complex between the two enzymes does not support the notion of a direct interaction between M-CK and enolase. This is the first demonstration of the presence of an enzyme of energy metabolism other than CK at the M-band of myofibres. |
| Databáze: | OpenAIRE |
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