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Takatsuki, Hideyo
Publications (6 of 6) Show all publications
Lindberg, F. W., Norrby, M., Rahman, M. A., Salhotra, A., Takatsuki, H., Jeppesen, S., . . . Månsson, A. (2018). Controlled Surface Silanization for Actin-Myosin and Biocompatibility of New Polymer Resists. Langmuir, 34(30), 8777-8784
Open this publication in new window or tab >>Controlled Surface Silanization for Actin-Myosin and Biocompatibility of New Polymer Resists
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2018 (English)In: Langmuir, ISSN 0743-7463, E-ISSN 1520-5827, Vol. 34, no 30, p. 8777-8784Article in journal (Refereed) Published
Abstract [en]

Molecular motor-based nanodevices require organized cytoskeletal filament guiding along motility-promoting tracks, confined by motility-inhibiting walls. One way to enhance motility quality on the tracks, particularly in terms of filament velocity but also the fraction of motile filaments, is to optimize the surface hydrophobicity. We have investigated the potential to achieve this for the actin myosin II motor system on trimethylchlorosilane (TMCS)-derivatized SiO2 surfaces to be used as channel floors in nanodevices. We have also investigated the ability to supress motility on two new polymer resists, TU7 (for nanoimprint lithography) and CSAR 62 (for electron beam and deep UV lithography), to be used as channel walls. We developed a chemical-vapor deposition tool for silanizing SiO2 surfaces in a controlled environment to achieve different surface hydrophobicities (measured by water contact angle). In contrast to previous work, we were able to fabricate a wide range of contact angles by varying the silanization time and chamber pressure using only one type of silane. This resulted in a significant improvement of the silanization procedure, producing a predictable contact angle on the surface and thereby predictable quality of the heavy meromyosin (HMM)-driven actin motility with regard to velocity. We observed a high degree of correlation between the filament sliding velocity and contact angle in the range 10-86 degrees, expanding the previously studied range. We found that the sliding velocity on TU7 surfaces was superior to that on CSAR 62 surfaces despite similar contact angles. In addition, we were able to suppress the motility on both TU7 and CSAR 62 by plasma oxygen treatment before silanization. These results are discussed in relation to previously proposed surface adsorption mechanisms of HMM and their relationship to the water contact angle. Additionally, the results are considered for the development of actin-myosin based nanodevices with superior performance with respect to actin-myosin functionality.

Place, publisher, year, edition, pages
American Chemical Society (ACS), 2018
National Category
Biophysics Biochemistry and Molecular Biology
Research subject
Chemistry, Biochemistry
Identifiers
urn:nbn:se:lnu:diva-77391 (URN)10.1021/acs.langmuir.8b01415 (DOI)000440768400007 ()29969272 (PubMedID)2-s2.0-85049637573 (Scopus ID)
Available from: 2018-08-30 Created: 2018-08-30 Last updated: 2019-08-29Bibliographically approved
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
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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: 2019-08-12Bibliographically approved
Kumar, S., Milani, G., Takatsuki, H., Lana, T., Persson, M., Frasson, C., . . . Månsson, A. (2016). Sensing protein antigen and microvesicle analytes using high-capacity biopolymer nano-carriers. The Analyst, 141(3), 836-846
Open this publication in new window or tab >>Sensing protein antigen and microvesicle analytes using high-capacity biopolymer nano-carriers
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2016 (English)In: The Analyst, ISSN 0003-2654, E-ISSN 1364-5528, Vol. 141, no 3, p. 836-846Article in journal (Refereed) Published
Abstract [en]

Lab-on-a-chip systems with molecular motor driven transport of analytes attached to cytoskeletal filament shuttles (actin filaments, microtubules) circumvent challenges with nanoscale liquid transport. However, the filaments have limited cargo-carrying capacity and limitations either in transportation speed (microtubules) or control over motility direction (actin). To overcome these constraints we here report incorporation of covalently attached antibodies into self-propelled actin bundles (nanocarriers) formed by cross-linking antibody conjugated actin filaments viafascin, a natural actin-bundling protein. We demonstrate high maximum antigen binding activity and propulsion by surface adsorbed myosin motors. Analyte transport capacity is tested using both protein antigens and microvesicles, a novel class of diagnostic markers. Increased incubation concentration with protein antigen in the 0.1–100 nM range (1 min) reduces the fraction of motile bundles and their velocity but maximum transportation capacity of >1 antigen per nm of bundle length is feasible. At sub-nanomolar protein analyte concentration, motility is very well preserved opening for orders of magnitude improved limit of detection using motor driven concentration on nanoscale sensors. Microvesicle-complexing to monoclonal antibodies on the nanocarriers compromises motility but nanocarrier aggregation via microvesicles shows unique potential in label-free detection with the aggregates themselves as non-toxic reporter elements.

National Category
Biochemistry and Molecular Biology
Research subject
Chemistry, Biochemistry
Identifiers
urn:nbn:se:lnu:diva-48641 (URN)10.1039/C5AN02377G (DOI)000368942600011 ()2-s2.0-84956748686 (Scopus ID)
Funder
Carl Tryggers foundation EU, FP7, Seventh Framework Programme
Available from: 2016-01-10 Created: 2016-01-10 Last updated: 2018-09-04Bibliographically approved
Takatsuki, H. & Månsson, A. (2015). Characterization and Stabilization of Fascin-Bundled Actin Filaments Transported by Heavy Meromyosin. Biophysical Journal, 108(2, Supplement 1), 299A-299A, Article ID 1496-Pos.
Open this publication in new window or tab >>Characterization and Stabilization of Fascin-Bundled Actin Filaments Transported by Heavy Meromyosin
2015 (English)In: Biophysical Journal, ISSN 0006-3495, E-ISSN 1542-0086, Vol. 108, no 2, Supplement 1, p. 299A-299A, article id 1496-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-47078 (URN)000362849100706 ()
Available from: 2015-11-06 Created: 2015-11-06 Last updated: 2017-12-01Bibliographically 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
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
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