Degradation of myosin light chain in isolated rat hearts subjected to ischemia-reperfusion injury: A new intracellular target for matrix metalloproteinase-2

Grzegorz Sawicki, Hernando Leon, Jolanta Sawicka, Meltem Sariahmetoglu, Costas J. Schulze, Paul G. Scott, Danuta Szczesna-Cordary, Richard Schulz

Research output: Contribution to journalArticlepeer-review

222 Scopus citations


Background - Matrix metalloproteinase-2 (MMP-2) contributes to cardiac dysfunction resulting from ischemia-reperfusion (I/R) injury. MMP-2 not only remodels the extracellular matrix but also acts intracellularly in I/R by degrading troponin I. Whether other intracellular targets exist for MMP-2 during I/R is unknown. Methods and Results - Isolated rat hearts were subjected to 20 minutes of ischemia and 30 minutes of reperfusion. The impaired recovery of mechanical function of the heart was attenuated by the MMP inhibitors o-phenanthroline or doxycycline. Quantitative 2D electrophoresis of homogenates of aerobically perfused hearts (control) or those subjected to I/R injury (in the presence or absence of MMP inhibitors) showed 3 low-molecular-weight proteins with levels that were significantly increased upon I/R injury and normalized to control levels by MMP inhibitors. Mass spectrometry analysis identified all 3 proteins as fragments of myosin light chain 1, which possesses theoretical cleavage recognition sequences for MMP-2 and is rapidly degraded by it in vitro. The association of MMP-2 with the thick myofilament in fractions prepared from I/R hearts was observed with immunogold electron microscopy, gelatin zymography for MMP-2 activity, and immunoprecipitation. MMP-2 was found to cleave myosin light chain 1 between tyrosine 189 and glutamine 190 at the C terminus. Conclusions - Our results demonstrate that myosin light chain 1 is another novel substrate for MMP-2 in the cardiomyocyte and that its degradation may contribute to contractile dysfunction resulting from I/R injury to the heart.

Original languageEnglish (US)
Pages (from-to)544-552
Number of pages9
Issue number4
StatePublished - Jul 26 2005


  • Metalloproteinases
  • Myocardial stunning
  • Myosin
  • Proteins
  • Reperfusion

ASJC Scopus subject areas

  • Physiology
  • Cardiology and Cardiovascular Medicine


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