title: Susceptibility of isolated myofibrils to in vitro glutathionylation: Potential relevance to muscle functions.
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 alpha-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 alpha-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 alpha-cardiac actin in human heart. Due to the critical location of alpha-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.
authors.affiliation: Children's Hospital and Research Institute "Bambino Gesù", Rome, Italy.
authors.forename: Chiara
authors.initials: C
authors.lastname: Passarelli
authors.forename: Almerinda
authors.initials: A
authors.lastname: Di Venere
authors.forename: Nicoletta
authors.initials: N
authors.lastname: Piroddi
authors.forename: Anna
authors.initials: A
authors.lastname: Pastore
authors.forename: Beatrice
authors.initials: B
authors.lastname: Scellini
authors.forename: Chiara
authors.initials: C
authors.lastname: Tesi
authors.forename: Stefania
authors.initials: S
authors.lastname: Petrini
authors.forename: Patrizio
authors.initials: P
authors.lastname: Sale
authors.forename: Enrico
authors.initials: E
authors.lastname: Bertini
authors.forename: Corrado
authors.initials: C
authors.lastname: Poggesi
authors.forename: Fiorella
authors.initials: F
authors.lastname: Piemonte
mesh_terms: D000199:Actins / Q000378:metabolism; D000818:Animals; D015153:Blotting, Western; D002851:Chromatography, High Pressure Liquid; D004797:Enzyme-Linked Immunosorbent Assay; D005455:Fluorescent Antibody Technique; D005978:Glutathione / Q000378:metabolism*; D006321:Heart / Q000502:physiology; D006801:Humans; D018613:Microscopy, Confocal; D018482:Muscle, Skeletal / Q000187:drug effects / Q000378:metabolism; D009206:Myocardium / Q000378:metabolism; D009210:Myofibrils / Q000187:drug effects / Q000378:metabolism*; D018384:Oxidative Stress; D046188:Protein Modification, Translational / Q000187:drug effects; D011817:Rabbits; D017382:Reactive Oxygen Species / Q000494:pharmacology
chemical_list: D000199:Actins; D017382:Reactive Oxygen Species; D005978:Glutathione