Nucleotide dependent differences between the {alpha}-skeletal and {alpha}-cardiac actin isoforms
- University of Pecs, Faculty of Medicine, Department of Biophysics, Pecs, Szigeti Str. 12, H-7624 (Hungary)
The thermodynamic properties of the actin filaments prepared from cardiomyocytes were investigated with differential scanning calorimetry. This method could distinguish between the {alpha}-cardiac and {alpha}-skeletal components of the actin filaments polymerised from ADP-actin monomers by their different melting temperatures (T{sub m}). Similar separation was not possible with filaments polymerised from ATP-actin monomers. Further analyses revealed that the activation energy (E{sub act}) was greater for filaments of {alpha}-skeletal actin than for {alpha}-cardiac actin monomers when the filaments were polymerised from ADP-actin monomers. These results showed that the {alpha}-cardiac actin filaments were thermodynamically less stable than the filaments of {alpha}-skeletal actin and their difference was nucleotide dependent. Based on these results and considering previous observations it was concluded that the existence of two actin isoforms and their nucleotide dependent conformational differences are part of the tuning regulatory mechanism by which the cardiac muscle cells can maintain their biological function under pathological conditions.
- OSTI ID:
- 21043704
- Journal Information:
- Biochemical and Biophysical Research Communications, Vol. 368, Issue 3; Other Information: DOI: 10.1016/j.bbrc.2008.01.158; PII: S0006-291X(08)00199-X; Copyright (c) 2008 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved; Country of input: International Atomic Energy Agency (IAEA); ISSN 0006-291X
- Country of Publication:
- United States
- Language:
- English
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