To Örebro University

oru.seÖrebro University Publications
Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
In Vitro Motility Assay Studies at Low [MgATP] - Evidence For Inter-Head Cooperativity in Fast Skeletal Myosin II
Linnaeus University, Kalmar, Sweden.ORCID iD: 0000-0003-2819-3046
Linnaeus University, Kalmar, Sweden.
Linnaeus University, Kalmar, Sweden.
Linnaeus University, Kalmar, Sweden.
Show others and affiliations
2012 (English)In: Biophysical Journal, ISSN 0006-3495, E-ISSN 1542-0086, Vol. 102, no 3 Suppl. 1, p. 146A-146AArticle in journal, Meeting abstract (Other academic) Published
Abstract [en]

The idea that fast skeletal myosin II exhibits processivity with sequential actions of the two myosin heads during muscle contraction has long been a topic of discussion but with appreciable difficulties to obtain conclusive experimental results. The difficulties may be related to a limited processivity (few sequential head actions) that is of greatest importance at low velocity (e.g. high resistive load), difficult to study accurately in vitro. In order to aid the investigations we here make use of recent evidence that the bipyridine drug amrinone inhibits the strain-dependent ADP-release step of myosin II with expected enhancement of processivity (Albet-Torres et al., J Biol Chem., 2009); Månsson, Biophys J., 2010). For accurate velocity measurements, the recombinant expressed capping protein CapZ (Soeno et. al., J Muscle Res Cell Motil., 1998) was fluorescence labeled. Nanometer tracking was achieved by two-dimensional Gaussian fits to single molecule fluorescence intensity profiles representing CapZ attached to the trailing actin filament end. Importantly, the heavy meromyosin (HMM) propelled actin filament sliding velocity (1mM MgATP) for CapZ-capped filaments was comparable to that of uncapped filaments at different ionic strengths and HMM surface densities. Studies at low [MgATP] (5-30mM) suggests a non-linearity in the [MgATP]-velocity plot that was enhanced by 1mM amrinone. The result is in contrast to the linearity expected for independent myosin heads and could be interpreted as an apparent velocity dependence of the myosin step length. This is in accordance with the idea of limited processivity of myosin II if it is assumed that a doubled apparent step length corresponds to sequential action of the two heads. Further insight into the mechanism will be obtained using proteolytically prepared one-headed HMM and e.g. studies with external loads on actin.

Place, publisher, year, edition, pages
Biophysical Society , 2012. Vol. 102, no 3 Suppl. 1, p. 146A-146A
National Category
Biophysics Biochemistry and Molecular Biology
Identifiers
URN: urn:nbn:se:oru:diva-99368DOI: 10.1016/j.bpj.2011.11.800ISI: 000321561201029OAI: oai:DiVA.org:oru-99368DiVA, id: diva2:1663369
Conference
56th Annual Meeting of the Biophysical-Society, San Diego, USA, February 25-29, 2012
Available from: 2022-06-02 Created: 2022-06-02 Last updated: 2022-06-08Bibliographically approved

Open Access in DiVA

No full text in DiVA

Other links

Publisher's full text

Authority records

Persson, Malin

Search in DiVA

By author/editor
Persson, Malin
In the same journal
Biophysical Journal
BiophysicsBiochemistry and Molecular Biology

Search outside of DiVA

GoogleGoogle Scholar

doi
urn-nbn

Altmetric score

doi
urn-nbn
Total: 14 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf