lnu.sePublications
Change search
Link to record
Permanent link

Direct link
BETA
Bengtsson, Elina
Publications (10 of 12) Show all publications
Bengtsson, E., Persson, M., Rahman, M. A., Kumar, S., Takatsuki, H. & Månsson, A. (2016). Myosin-Induced Gliding Patterns at Varied [MgATP] Unveil a Dynamic Actin Filament. Biophysical Journal, 111(7), 1465-1477
Open this publication in new window or tab >>Myosin-Induced Gliding Patterns at Varied [MgATP] Unveil a Dynamic Actin Filament
Show others...
2016 (English)In: Biophysical Journal, ISSN 0006-3495, E-ISSN 1542-0086, Vol. 111, no 7, p. 1465-1477Article in journal (Refereed) Published
Abstract [en]

Actin filaments have key roles in cell motility but are generally claimed to be passive interaction partners in actin-myosin -based motion generation. Here, we present evidence against this static view based on an altered myosin-induced actin filament gliding pattern in an in vitro motility assay at varied [MgATP]. The statistics that characterize the degree of meandering of the actin filament paths suggest that for [MgATP] >= 0.25 mM, the flexural rigidity of heavy meromyosin (HMM)-propelled actin filaments is similar (without phalloidin) or slightly lower (with phalloidin) than that of HMM-free filaments observed in solution without surface tethering. When [MgATP] was reduced to <= 0.1 mM, the actin filament paths in the in vitro motility assay became appreciably more winding in both the presence and absence of phalloidin. This effect of lowered [MgATP] was qualitatively different from that seen when HMM was mixed with ATP-insensitive, N-ethylmaleimide-treated HMM (NEM-HMM; 25-30%). In particular, the addition of NEM-HMM increased a non-Gaussian tail in the path curvature distribution as well as the number of events in which different parts of an actin filament followed different paths. These effects were the opposite of those observed with reduced [MgATP]. Theoretical modeling suggests a 30-40% lowered flexural rigidity of the actin filaments at [MgATP] <= 0.1 mM and local bending of the filament front upon each myosin head attachment. Overall, the results fit with appreciable structural changes in the actin filament during actomyosin-based motion generation, and modulation of the actin filament mechanical properties by the dominating chemomechanical actomyosin state.

National Category
Biophysics Biochemistry and Molecular Biology
Research subject
Chemistry, Biochemistry
Identifiers
urn:nbn:se:lnu:diva-58085 (URN)10.1016/j.bpj.2016.08.025 (DOI)000385471500013 ()27705769 (PubMedID)2-s2.0-85002888273 (Scopus ID)
Available from: 2016-11-11 Created: 2016-11-11 Last updated: 2019-02-22Bibliographically approved
Nicolau, D. V. ., Lard, M., Korten, T., van Delftf, F. C. M., Persson, M., Bengtsson, E., . . . Nicolau, D. V. (2016). Parallel computation with molecular-motor-propelled agents in nanofabricated networks. Proceedings of the National Academy of Sciences of the United States of America, 113(10), 2591-2596
Open this publication in new window or tab >>Parallel computation with molecular-motor-propelled agents in nanofabricated networks
Show others...
2016 (English)In: Proceedings of the National Academy of Sciences of the United States of America, ISSN 0027-8424, E-ISSN 1091-6490, Vol. 113, no 10, p. 2591-2596Article in journal (Refereed) Published
Abstract [en]

The combinatorial nature of many important mathematical problems, including nondeterministic-polynomial-time (NP)-complete problems, places a severe limitation on the problem size that can be solved with conventional, sequentially operating electronic computers. There have been significant efforts in conceiving parallel-computation approaches in the past, for example: DNA computation, quantum computation, and microfluidics-based computation. However, these approaches have not proven, so far, to be scalable and practical from a fabrication and operational perspective. Here, we report the foundations of an alternative parallel-computation system in which a given combinatorial problem is encoded into a graphical, modular network that is embedded in a nanofabricated planar device. Exploring the network in a parallel fashion using a large number of independent, molecular-motor-propelled agents then solves the mathematical problem. This approach uses orders of magnitude less energy than conventional computers, thus addressing issues related to power consumption and heat dissipation. We provide a proof-of-concept demonstration of such a device by solving, in a parallel fashion, the small instance {2, 5, 9} of the subset sum problem, which is a benchmark NP-complete problem. Finally, we discuss the technical advances necessary to make our system scalable with presently available technology.

Keywords
parallel computing, molecular motors, NP complete, biocomputation, nanotechnology
National Category
Chemical Sciences
Research subject
Natural Science, Chemistry
Identifiers
urn:nbn:se:lnu:diva-51981 (URN)10.1073/pnas.1510825113 (DOI)000372013300025 ()26903637 (PubMedID)2-s2.0-84960532489 (Scopus ID)
External cooperation:
Available from: 2016-04-08 Created: 2016-04-08 Last updated: 2017-11-30Bibliographically approved
Nicolau, D. V. ., Lard, M., Korten, T., van Delft, F. C. M., Persson, M., Bengtsson, E., . . . Nicolau, D. V. (2016). REPLY TO EINARSSON: The computational power of parallel network exploration with many bioagents [Letter to the editor]. Proceedings of the National Academy of Sciences of the United States of America, 113(23), E3188-E3188
Open this publication in new window or tab >>REPLY TO EINARSSON: The computational power of parallel network exploration with many bioagents
Show others...
2016 (English)In: Proceedings of the National Academy of Sciences of the United States of America, ISSN 0027-8424, E-ISSN 1091-6490, Vol. 113, no 23, p. E3188-E3188Article in journal, Letter (Refereed) Published
National Category
Chemical Sciences
Research subject
Natural Science, Chemistry
Identifiers
urn:nbn:se:lnu:diva-54681 (URN)10.1073/pnas.1605214113 (DOI)000377155400002 ()27226290 (PubMedID)
Available from: 2016-07-22 Created: 2016-07-21 Last updated: 2017-11-28Bibliographically approved
Bengtsson, E., Persson, M., Kumar, S. & Månsson, A. (2015). Altered Structural State of Actin Filaments Upon MYOSIN II Binding. Biophysical Journal, 108(2 Supplement 1), 299A-300A, Article ID 1499-Pos.
Open this publication in new window or tab >>Altered Structural State of Actin Filaments Upon MYOSIN II Binding
2015 (English)In: Biophysical Journal, ISSN 0006-3495, E-ISSN 1542-0086, Vol. 108, no 2 Supplement 1, p. 299A-300A, article id 1499-PosArticle in journal, Meeting abstract (Other academic) Published
National Category
Biochemistry and Molecular Biology
Research subject
Natural Science, Biomedical Sciences
Identifiers
urn:nbn:se:lnu:diva-47077 (URN)000362849100709 ()
Available from: 2015-11-06 Created: 2015-11-06 Last updated: 2017-12-01Bibliographically approved
Persson, M., Bengtsson, E., ten Siethoff, L. & Månsson, A. (2014). Non-Linear Cross-Bridge Elasticity, ATP-Independent Detachment and ATP-Velocity Relationships for Skeletal Muscle Actomyosin. Paper presented at 58th Annual Meeting of the Biophysical-Society, FEB 15-19, 2014, San Francisco, CA. Biophysical Journal, 106(2), 158A-158A
Open this publication in new window or tab >>Non-Linear Cross-Bridge Elasticity, ATP-Independent Detachment and ATP-Velocity Relationships for Skeletal Muscle Actomyosin
2014 (English)In: Biophysical Journal, ISSN 0006-3495, E-ISSN 1542-0086, Vol. 106, no 2, p. 158A-158AArticle in journal, Meeting abstract (Other academic) Published
National Category
Biochemistry and Molecular Biology
Research subject
Natural Science, Biomedical Sciences
Identifiers
urn:nbn:se:lnu:diva-36106 (URN)000337000400783 ()
Conference
58th Annual Meeting of the Biophysical-Society, FEB 15-19, 2014, San Francisco, CA
Available from: 2014-07-17 Created: 2014-07-17 Last updated: 2017-12-05Bibliographically approved
Takatsuki, H., Bengtsson, E. & Månsson, A. (2014). Persistence length of fascin-cross-linked actin filament bundles in solution and the in vitro motility assay. Biochimica et Biophysica Acta - General Subjects, 1840(6), 1933-1942
Open this publication in new window or tab >>Persistence length of fascin-cross-linked actin filament bundles in solution and the in vitro motility assay
2014 (English)In: Biochimica et Biophysica Acta - General Subjects, ISSN 0304-4165, E-ISSN 1872-8006, Vol. 1840, no 6, p. 1933-1942Article in journal (Refereed) Published
Abstract [en]

Background: Bundles of unipolar actin filaments (F-actin), cross-linked via the actin-binding protein fascin, are important in filopodia of motile cells and stereocilia of inner ear sensory cells. However, such bundles are also useful as shuttles in myosin-driven nanotechnological applications. Therefore, and for elucidating aspects of biological function, we investigate if the bundle tendency to follow straight paths (quantified by path persistence length) when propelled by myosin motors is directly determined by material properties quantified by persistence length of thermally fluctuating bundles. Methods: Fluorescent bundles, labeled with rhodamine-phalloidin, were studied at fascin:actin molar ratios: 0:1 (F-actin), 1:7, 1:4 and 1:2. Persistence lengths (Lp) were obtained by fitting the cosine correlation function (CCF) to a single exponential function: <cos(theta(0) theta(s)) > = exp(-s / (2Lp)) where theta(s) is tangent angle; s: path or contour lengths. < > denotes averaging over filaments. Results: Bundle-Lp (bundles < 15 mu m long) increased from similar to 10 to 150 mu m with increased fascin:actin ratio. The increase was similar for path-Lp (path < 15 mu m), with highly linear correlation. For longer bundle paths, the CCF-decay deviated from a single exponential, consistent with superimposition of the random path with a circular path as suggested by theoretical analysis. Conclusions: Fascin-actin bundles have similar path-Lp and bundle-Lp, both increasing with fascin:actin ratio. Path-Lp is determined by the flexural rigidity of the bundle. General significance: The findings give general insight into mechanics of cytoskeletal polymers that interact with molecular motors, aid rational development of nanotechnological applications and have implications for structure and in vivo functions of fascin-actin bundles. (C) 2014 The Authors. Published by Elsevier B.V.

Keywords
Persistence length, Fascin, Actin, Myosin, Motility assay, Monte-Carlo simulation
National Category
Biochemistry and Molecular Biology
Research subject
Natural Science, Biomedical Sciences
Identifiers
urn:nbn:se:lnu:diva-36153 (URN)10.1016/j.bbagen.2014.01.012 (DOI)000336012700034 ()2-s2.0-84897059544 (Scopus ID)
Available from: 2014-07-17 Created: 2014-07-17 Last updated: 2017-12-05Bibliographically approved
Bengtsson, E., Persson, M., Kumar, S. & Månsson, A. (2013). Actomyosin Interactions and Different Structural States of Actin Filaments. Paper presented at 57th Annual Meeting of the Biophysical-Society, FEB 02-06, 2013, Philadelphia, PA. Biophysical Journal, 104(2), 480A-481A
Open this publication in new window or tab >>Actomyosin Interactions and Different Structural States of Actin Filaments
2013 (English)In: Biophysical Journal, ISSN 0006-3495, E-ISSN 1542-0086, Vol. 104, no 2, p. 480A-481AArticle in journal, Meeting abstract (Other academic) Published
National Category
Biophysics
Research subject
Natural Science, Biomedical Sciences
Identifiers
urn:nbn:se:lnu:diva-25492 (URN)000316074304440 ()
Conference
57th Annual Meeting of the Biophysical-Society, FEB 02-06, 2013, Philadelphia, PA
Available from: 2013-05-02 Created: 2013-05-02 Last updated: 2017-12-06Bibliographically approved
Bengtsson, E., Persson, M. & Månsson, A. (2013). Analysis of Flexural Rigidity of Actin Filaments Propelled by Surface Adsorbed Myosin Motors. Cytoskeleton, 70(11), 718-728
Open this publication in new window or tab >>Analysis of Flexural Rigidity of Actin Filaments Propelled by Surface Adsorbed Myosin Motors
2013 (English)In: Cytoskeleton, ISSN 1949-3584, Vol. 70, no 11, p. 718-728Article in journal (Refereed) Published
Abstract [en]

Actin filaments are central components of the cytoskeleton and the contractile machinery of muscle. The filaments are known to exist in a range of conformational states presumably with different flexural rigidity and thereby different persistence lengths. Our results analyze the approaches proposed previously to measure the persistence length from the statistics of the winding paths of actin filaments that are propelled by surface-adsorbed myosin motor fragments in the in vitro motility assay. Our results suggest that the persistence length of heavy meromyosin propelled actin filaments can be estimated with high accuracy and reproducibility using this approach provided that: (1) the in vitro motility assay experiments are designed to prevent bias in filament sliding directions, (2) at least 200 independent filament paths are studied, (3) the ratio between the sliding distance between measurements and the camera pixel-size is between 4 and 12, (4) the sliding distances between measurements is less than 50% of the expected persistence length, and (5) an appropriate cut-off value is chosen to exclude abrupt large angular changes in sliding direction that are complications, e.g., due to the presence of rigor heads. If the above precautions are taken the described method should be a useful routine part of in vitro motility assays thus expanding the amount of information to be gained from these. (c) 2013 Wiley Periodicals, Inc.

Keywords
actin, cytoskeletal filament, Monte-Carlo simulations, molecular motor
National Category
Biochemistry and Molecular Biology
Research subject
Natural Science, Biomedical Sciences
Identifiers
urn:nbn:se:lnu:diva-31271 (URN)10.1002/cm.21138 (DOI)000327310200004 ()2-s2.0-84888199072 (Scopus ID)
Available from: 2013-12-16 Created: 2013-12-16 Last updated: 2018-05-21Bibliographically approved
Takatsuki, H., Bengtsson, E. & Månsson, A. (2013). Flexural Rigidity of Actin Bundles Propelled by Heavy Meromyosin. Paper presented at 57th Annual Meeting of the Biophysical-Society, FEB 02-06, 2013, Philadelphia, PA. Biophysical Journal, 104(2), 649A-649A
Open this publication in new window or tab >>Flexural Rigidity of Actin Bundles Propelled by Heavy Meromyosin
2013 (English)In: Biophysical Journal, ISSN 0006-3495, E-ISSN 1542-0086, Vol. 104, no 2, p. 649A-649AArticle in journal, Meeting abstract (Other academic) Published
National Category
Biophysics
Research subject
Natural Science, Biomedical Sciences
Identifiers
urn:nbn:se:lnu:diva-25493 (URN)000316074306279 ()
Conference
57th Annual Meeting of the Biophysical-Society, FEB 02-06, 2013, Philadelphia, PA
Available from: 2013-05-02 Created: 2013-05-02 Last updated: 2017-12-06Bibliographically approved
Persson, M., Bengtsson, E., ten Siethoff, L. & Månsson, A. (2013). Nonlinear Cross-Bridge Elasticity and Post-Power-Stroke Events in Fast Skeletal Muscle Actomyosin. Biophysical Journal, 105(8), 1871-1881
Open this publication in new window or tab >>Nonlinear Cross-Bridge Elasticity and Post-Power-Stroke Events in Fast Skeletal Muscle Actomyosin
2013 (English)In: Biophysical Journal, ISSN 0006-3495, E-ISSN 1542-0086, Vol. 105, no 8, p. 1871-1881Article in journal (Refereed) Published
Abstract [en]

Generation-of force and movement by actomyosin cross-bridges is the molecular basis of muscle contraction, but generally accepted ideas about cross-bridge properties have recently been questioned. Of the utmost significance, evidence for nonlinear cross-bridge elasticity has been presented. We here investigate how this and other newly discovered or postulated phenomena would modify cross-bridge operation, with focus on post-power-stroke events. First, as an experimental basis, we present evidence for a hyperbolic [MgATP]-velocity relationship of heavy-meromyosin-propelled actin filaments in the in vitro motility assay using fast rabbit skeletal muscle myosin (28-29 degrees C). As the hyperbolic [MgATP]-velocity relationship was not consistent with interhead cooperativity, we developed a cross-bridge model with independent myosin heads and strain-dependent interstate transition rates. The model, implemented with inclusion of MgATP-independent detachment from the rigor state, as suggested by previous single-molecule mechanics experiments, accounts well for the [MgATP]-velocity relationship if nonlinear cross-bridge elasticity is assumed, but not if linear cross-bridge elasticity is assumed. In addition, a better fit is obtained with load-independent than with load-dependent MgATP-induced detachment rate. We discuss our results in relation to previous data showing a nonhyperbolic [MgATP1-velocity relationship when actin filaments are propelled by myosin subfragment 1 or full-length myosin. We also consider the implications of our results for characterization of the cross-bridge elasticity in the filament lattice of muscle.

National Category
Biophysics
Research subject
Natural Science, Biomedical Sciences
Identifiers
urn:nbn:se:lnu:diva-30999 (URN)10.1016/j.bpj.2013.08.044 (DOI)000325838500017 ()2-s2.0-84886005960 (Scopus ID)
Available from: 2013-12-06 Created: 2013-12-06 Last updated: 2017-12-06Bibliographically approved
Organisations

Search in DiVA

Show all publications