| First Author | Merkulova T | Year | 1997 |
| Journal | Biochem J | Volume | 323 ( Pt 3) |
| Pages | 791-800 | PubMed ID | 9169614 |
| Mgi Jnum | J:318719 | Mgi Id | MGI:6861803 |
| Doi | 10.1042/bj3230791 | Citation | Merkulova T, et al. (1997) Biochemical characterization of the mouse muscle-specific enolase: developmental changes in electrophoretic variants and selective binding to other proteins. Biochem J 323((Pt 3)):791-800 |
| abstractText | The glycolytic enzyme enolase (EC 4.2.1.11) is active as dimers formed from three subunits encoded by different genes. The embryonic alphaalpha isoform remains distributed in many adult cell types, whereas a transition towards betabeta and gammagamma isoforms occurs in striated muscle cells and neurons respectively. It is not understood why enolase exhibits tissue-specific isoforms with very close functional properties. We approached this problem by the purification of native betabeta-enolase from mouse hindlimb muscles and by raising specific antibodies of high titre against this protein. These reagents have been useful in revealing a heterogeneity of the beta-enolase subunit that changes with in vivo and in vitro maturation. A basic carboxypeptidase appears to be involved in generating an acidic beta-enolase variant, and may regulate plasminogen binding by this subunit. We show for the first time that pure betabeta-enolase binds with high affinity the adjacent enzymes in the glycolytic pathway (pyruvate kinase and phosphoglycerate mutase), favouring the hypothesis that these three enzymes form a functional glycolytic segment. betabeta-Enolase binds with high affinity sarcomeric troponin but not actin and tropomyosin. Some of these binding properties are shared by the alphaalpha-isoenolase, which is also expressed in striated muscle, but not by the neuron-specific gammagamma-enolase. These results support the idea that specific interactions with macromolecules will address muscle enolase isoforms at the subcellular site where ATP, produced through glycolysis, is most needed for contraction. Such a specific targeting could be modulated by post-translational modifications. |
