Dynamics of tropomyosin in muscle fibers as monitored by saturation transfer EPR of bi-functional probe

Roni F. Rayes, Tamás Kálai, Kálmán Hideg, Michael A. Geeves, Piotr G. Fajer

Research output: Contribution to journalArticle

13 Citations (Scopus)

Abstract

The dynamics of four regions of tropomyosin was assessed using saturation transfer electron paramagnetic resonance in the muscle fiber. In order to fully immobilize the spin probe on the surface of tropomyosin, a bi-functional spin label was attached to i,i+4 positions via cysteine mutagenesis. The dynamics of bi-functionally labeled tropomyosin mutants decreased by three orders of magnitude when reconstituted into "ghost muscle fibers". The rates of motion varied along the length of tropomyosin with the C-terminus position 268/272 being one order of magnitude slower then N-terminal domain or the center of the molecule. Introduction of troponin decreases the dynamics of all four sites in the muscle fiber, but there was no significant effect upon addition of calcium or myosin subfragment-1.

Original languageEnglish
Article numbere21277
JournalPloS one
Volume6
Issue number6
DOIs
Publication statusPublished - 2011

ASJC Scopus subject areas

  • Biochemistry, Genetics and Molecular Biology(all)
  • Agricultural and Biological Sciences(all)
  • General

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