Susceptibility of isolated myofibrils to in vitro glutathionylation: Potential relevance to muscle functions

Chiara Passarelli, Almerinda Di Venere, Nicoletta Piroddi, Anna Pastore, Beatrice Scellini, Chiara Tesi, Stefania Petrini, Patrizio Sale, Enrico Bertini, Corrado Poggesi, Fiorella Piemonte

Research output: Contribution to journalArticle

Abstract

In this study we investigated the molecular mechanism of glutathionylation on isolated human cardiac myofibrils using several pro-glutathionylating agents. Total glutathionylated proteins appeared significantly enhanced with all the pro-oxidants used. The increase was completely reversed by the addition of a reducing agent, demonstrating that glutathione binding occurs by a disulfide and that the process is reversible. A sensitive target of glutathionylation was α-actin, showing a different reactivity to the several pro-glutathionylating agents by ELISA. Noteworthy, myosin although highly sensitive to the in vitro glutathionylation does not represent the primary glutathionylation target in isolated myofibrils. Light scattering measurements of the glutathionylated α-actin showed a slower polymerisation compared to the non-glutathionylated protein and force development was depressed after glutathionylation, when the myofibrils were mounted in a force recording apparatus. Interestingly, confocal laser scanning microscopy of cardiac cryosections indicated, for the first time, the constitutive glutathionylation of α-cardiac actin in human heart. Due to the critical location of α-actin in the contractile machinery and to its susceptibility to the oxidative modifications, glutathionylation may represent a mechanism for modulating sarcomere assembly and muscle functionality under patho-physiological conditions in vivo.

Original languageEnglish
Pages (from-to)81-89
Number of pages9
JournalCytoskeleton
Volume67
Issue number2
DOIs
Publication statusPublished - 2010

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Keywords

  • Actin
  • Glutathione
  • Glutathionylated proteins
  • Myofibrils
  • Oxidative stress

ASJC Scopus subject areas

  • Cell Biology
  • Structural Biology
  • Medicine(all)

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