Journal of Thermal Analysis and Calorimetry

, Volume 82, Issue 1, pp 287–290 | Cite as

Thermodynamic characterization of different actin isoforms

  • J. Orbán
  • Sz. Halasi
  • G. Papp
  • Szilvia Barkó
  • Beáta Bugyi

Summary

The thermodynamic properties of the cardiac and skeletal a-actin isoforms were studied to characterize the molecular bases of the functional differences between them with the method of differential scanning calorimetry (DSC). The thermal properties of the actin filaments were described in the presence of calcium and magnesium ions as well. Based on the calculated free energy changes the α-cardiac actin filaments appeared to be more stable in its physiologically more relevant, magnesium saturated form. The magnesium saturated form of the α-cardiac actin filaments seemed to be more stable compared to the calcium saturated form of it. The enthalpy and entropy changes could differentiate between the α-cardiac and α-skeletal actin isoforms and between the calcium and magnesium saturated cardiac actin isoforms as well. Our results can demonstrate that the few differences between the amino acid sequences of the α-actin isoforms have an influence on the thermal properties and maybe on the function of these proteins as well.

calorimetry thermodynamics divalent cation cardiac actin skeletal actin 

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

Copyright information

© Springer-Verlag/Akadémiai Kiadó 2005

Authors and Affiliations

  • J. Orbán
    • 1
  • Sz. Halasi
    • 2
  • G. Papp
    • 3
  • Szilvia Barkó
    • 4
  • Beáta Bugyi
    • 5
  1. 1.University of Pécs, Faculty of Medicine, Department of Biophysics
  2. 2.University of Pécs, Faculty of Medicine, Department of Biophysics
  3. 3.University of Pécs, Faculty of Medicine, Department of Biophysics
  4. 4.University of Pécs, Faculty of Medicine, Department of Biophysics
  5. 5.University of Pécs, Faculty of Medicine, Department of Biophysics

Personalised recommendations