The regulatory domain of the myosin head behaves as a rigid lever

B. A J Baumann, B. D. Hambly, K. Hideg, P. G. Fajer

Research output: Contribution to journalArticle

13 Citations (Scopus)

Abstract

The regulatory domain of the myosin head is believed to serve as a lever arm that amplifies force generated in the catalytic domain and transmits this strain to the thick filament. The lever arm itself either can be passive or may have a more active role storing some of the energy created by hydrolysis of ATP. A structural correlate which might distinguish between these two possibilities (a passive or an active role) is the stiffness of the domain in question. To this effect we have examined the motion of the proximal (ELC) and distal (RLC) subdomains of the regulatory domain in reconstituted myosin filaments. Each subdomain was labeled with a spin label at a unique cysteine residue, Cys-136 of ELC or Cys-154 of mutant RLC, and its mobility was determined using saturation transfer electron paramagnetic resonance spectroscopy. The mobility of the two domains was similar; the effective correlation time (τeff) for ELC was 17 μs and that for RLC was 22 μs. Additionally, following a 2-fold change of the global dynamics of the myosin head, effected by decreasing the interactions with the filament surface (or the other myosin head), the coupling of the intradomain dynamics remained unchanged. These data suggest that the regulatory domain of the myosin head acts as a single mechanically rigid body, consistent with the regulatory domain serving as a passive lever.

Original languageEnglish
Pages (from-to)7868-7873
Number of pages6
JournalBiochemistry
Volume40
Issue number26
DOIs
Publication statusPublished - Jul 3 2001

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Myosins
Spin Labels
Electron Spin Resonance Spectroscopy
Cysteine
Paramagnetic resonance
Hydrolysis
Catalytic Domain
Spectrum Analysis
Adenosine Triphosphate
Stiffness
Spectroscopy

ASJC Scopus subject areas

  • Biochemistry

Cite this

The regulatory domain of the myosin head behaves as a rigid lever. / Baumann, B. A J; Hambly, B. D.; Hideg, K.; Fajer, P. G.

In: Biochemistry, Vol. 40, No. 26, 03.07.2001, p. 7868-7873.

Research output: Contribution to journalArticle

Baumann, BAJ, Hambly, BD, Hideg, K & Fajer, PG 2001, 'The regulatory domain of the myosin head behaves as a rigid lever', Biochemistry, vol. 40, no. 26, pp. 7868-7873. https://doi.org/10.1021/bi002731h
Baumann, B. A J ; Hambly, B. D. ; Hideg, K. ; Fajer, P. G. / The regulatory domain of the myosin head behaves as a rigid lever. In: Biochemistry. 2001 ; Vol. 40, No. 26. pp. 7868-7873.
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