lnu.sePublications
Change search
Refine search result
1 - 4 of 4
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • harvard1
  • 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
Rows per page
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sort
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
Select
The maximal number of hits you can export is 250. When you want to export more records please use the Create feeds function.
  • 1.
    Månsson, Alf
    Linnaeus University, Faculty of Health and Life Sciences, Department of Chemistry and Biomedical Sciences.
    Actomyosin based contraction: one mechanokinetic model from single molecules to muscle?2016In: Journal of Muscle Research and Cell Motility, ISSN 0142-4319, E-ISSN 1573-2657, Vol. 37, no 6, p. 181-194Article in journal (Refereed)
    Abstract [en]

    Bridging the gaps between experimental systems on different hierarchical scales is needed to overcome remaining challenges in the understanding of muscle contraction. Here, a mathematical model with well-characterized structural and biochemical actomyosin states is developed to that end. We hypothesize that this model accounts for generation of force and motion from single motor molecules to the large ensembles of muscle. In partial support of this idea, a wide range of contractile phenomena are reproduced without the need to invoke cooperative interactions or ad hoc states/transitions. However, remaining limitations exist, associated with ambiguities in available data for model definition e.g.: (1) the affinity of weakly bound cross-bridges, (2) the characteristics of the cross-bridge elasticity and (3) the exact mechanistic relationship between the force-generating transition and phosphate release in the actomyosin ATPase. Further, the simulated number of attached myosin heads in the in vitro motility assay differs several-fold from duty ratios, (fraction of strongly attached ATPase cycle times) derived in standard analysis. After addressing the mentioned issues the model should be useful in fundamental studies, for engineering of myosin motors as well as for studies of muscle disease and drug development.

  • 2.
    Månsson, Alf
    Linnaeus University, Faculty of Health and Life Sciences, Department of Chemistry and Biomedical Sciences.
    The effects of inorganic phosphate on muscle force development and energetics: challenges in modelling related to experimental uncertainties2019In: Journal of Muscle Research and Cell Motility, ISSN 0142-4319, E-ISSN 1573-2657Article in journal (Refereed)
    Abstract [en]

    Muscle force and power are developed by myosin cross-bridges, which cyclically attach to actin, undergo a force-generating transition and detach under turnover of ATP. The force-generating transition is intimately associated with release of inorganic phosphate (Pi) but the exact sequence of events in relation to the actual Pi release step is controversial. Details of this process are reflected in the relationships between [Pi] and the developed force and shortening velocity. In order to account for these relationships, models have proposed branched kinetic pathways or loose coupling between biochemical and force-generating transitions. A key hypothesis underlying the present study is that such complexities are not required to explain changes in the force-velocity relationship and ATP turnover rate with altered [Pi]. We therefore set out to test if models without branched kinetic paths and Pi-release occurring before the main force-generating transition can account for effects of varied [Pi] (0.1-25 mM). The models tested, one assuming either linear or non-linear cross-bridge elasticity, account well for critical aspects of muscle contraction at 0.5 mM Pi but their capacity to account for the maximum power output vary. We find that the models, within experimental uncertainties, account for the relationship between [Pi] and isometric force as well as between [Pi] and the velocity of shortening at low loads. However, in apparent contradiction with available experimental findings, the tested models produce an anomalous force-velocity relationship at elevated [Pi] and high loads with more than one possible velocity for a given load. Nevertheless, considering experimental uncertainties and effects of sarcomere non-uniformities, these discrepancies are insufficient to refute the tested models in favour of more complex alternatives.

  • 3.
    Månsson, Alf
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Translational actomyosin research: fundamental insights and applications hand in hand.2012In: Journal of Muscle Research and Cell Motility, ISSN 0142-4319, E-ISSN 1573-2657, Vol. 33, no 3-4, p. 219-233Article, review/survey (Refereed)
    Abstract [en]

    This review describes the development towards actomyosin based nanodevices taking a starting point in pioneering studies in the 1990s based on conventional in vitro motility assays. References are given to parallel developments using the kinesin-microtubule motor system. The early developments focused on achieving cargo-transportation using actin filaments as cargo-loaded shuttles propelled by surface-adsorbed heavy meromyosin along micro- and nanofabricated channels. These efforts prompted extensive studies of surface-motor interactions contributing with new insights of general relevance in surface and colloid chemistry. As a result of these early efforts, a range of complex devices have now emerged, spanning applications in medical diagnostics, biocomputation and formation of complex nanostructures by self-organization. In addition to giving a comprehensive account of the developments towards real-world applications an important goal of the present review is to demonstrate important connections between the applied studies and fundamental biophysical studies of actomyosin and muscle function. Thus the manipulation of the motor proteins towards applications has resulted in new insights into methodological aspects of the in vitro motiliy assay. Other developments have advanced the understanding of the dynamic materials properties of actin filaments.

  • 4.
    Rahman, Mohammad A.
    et al.
    Linnaeus University, Faculty of Health and Life Sciences, Department of Chemistry and Biomedical Sciences.
    Salhotra, Aseem
    Linnaeus University, Faculty of Health and Life Sciences, Department of Chemistry and Biomedical Sciences.
    Månsson, Alf
    Linnaeus University, Faculty of Health and Life Sciences, Department of Chemistry and Biomedical Sciences.
    Comparative analysis of widely used methods to remove nonfunctional myosin heads for the in vitro motility assay2018In: Journal of Muscle Research and Cell Motility, ISSN 0142-4319, E-ISSN 1573-2657, Vol. 39, no 5-6, p. 175-187Article in journal (Refereed)
    Abstract [en]

    The in vitro motility assay allows studies of muscle contraction through observation of actin filament propulsion by surface-adsorbed myosin motors or motor fragments isolated from muscle. A possible problem is that motility may be compromised by nonfunctional, "dead", motors, obtained in the isolation process. Here we investigate the effects on motile function of two approaches designed to eliminate the effects of these dead motors. We first tested the removal of heavy meromyosin (HMM) molecules with ATP-insensitive "dead" heads by pelleting them with actin filaments, using ultracentrifugation in the presence of 1 mM MgATP ("affinity purification"). Alternatively we incubated motility assay flow cells, after HMM surface adsorption, with non-fluorescent "blocking actin" (1 µM) to block the dead heads. Both affinity purification and use of blocking actin increased the fraction of motile filaments compared to control conditions. However, affinity purification significantly reduced the actin sliding speed in five out of seven experiments on silanized surfaces and in one out of four experiments on nitrocellulose surfaces. Similar effects on velocity were not observed with the use of blocking actin. However, a reduced speed was also seen (without affinity purification) if HMM or myosin subfragment 1 was mixed with 1 mM MgATP before and during surface adsorption. We conclude that affinity purification can produce unexpected effects that may complicate the interpretation of in vitro motility assays and other experiments with surface adsorbed HMM, e.g. single molecule mechanics experiments. The presence of MgATP during incubation with myosin motor fragments is critical for the complicating effects.

1 - 4 of 4
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • harvard1
  • 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