| 1. |
- Bunk, Richard, et al.
(författare)
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Guiding molecular motors with nano-imprinted structures
- 2005
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Ingår i: Japanese Journal of Applied Physics. - 0021-4922. ; 44:5A, s. 3337-3340
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Tidskriftsartikel (refereegranskat)abstract
- This work, for the first time, demonstrates that nano-imprinted samples, with 100 nm wide polymer lines, can act as guides for molecular motors consisting of motor proteins actin and myosin. The motor protein function was characterized using fluorescence microscopy and compared to actomyosin motility on non-structured nitrocellulose surfaces. Our results open for further use of the nano-imprint technique in the production of disposable chips for bio-nanotechnological applications and miniaturized biological test systems. We discuss how the nano-imprinted motor protein assay system may be optimized and also how it compares to previously tested assay systems involving low-resolution UV-lithography and low throughput but high-resolution electron beam lithography.
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| 2. |
- Bunk, Richard, et al.
(författare)
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Guiding motor-propelled molecules with nanoscale precision through silanized bi-channel structures
- 2005
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Ingår i: Nanotechnology. - : IOP Publishing. - 0957-4484 .- 1361-6528. ; 16:6, s. 710-717
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Tidskriftsartikel (refereegranskat)abstract
- We report on the design and fabrication of a channel structure for high precision guidance and achieving excellent confinement properties for motor-propelled molecular shuttles. The techniques used to manufacture the channel structure are mainly e-beam lithography and selective monolayer functionalization. The structure consists of two lateral layers of concentric channels on a SiO2 surface made biocompatible with the molecular motors. The quality and advantages of the design are demonstrated by experiments using the motor proteins actin and myosin. The special channel geometry leads to stable biochemical conditions with full motor protein functionality. ATP is sufficiently supplied to all parts of the structure by dedicated service channels, as is the venting of ADP and P-i (inorganic phosphorus). Channels of different widths (100-700 nm) and shapes are fabricated and measurements made on them.
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| 3. |
- Mansson, A, et al.
(författare)
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Actin-based molecular motors for cargo transportation in nanotechnology - Potentials and challenges
- 2005
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Ingår i: IEEE Transactions on Advanced Packaging. - 1521-3323. ; 28:4, s. 547-555
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Tidskriftsartikel (refereegranskat)abstract
- Here, we review the use of actin-based motors, (myosins; e.g., the molecular motor of muscle) in. nanotechnology. The review starts from the viewpoints of the molecular motors as being important devices responsible of cargo transportation in the cell and end in discussions about their employment in nanotechnological applications. First, we describe basic biophysics of the myosin motors with focus on their involvement in cargo transportation in the living cell, leading us over into a discussion about in vitro motility assays. These are biological test systems where the myosin-induced translocation of actin filaments is studied on an artificial surface outside the cell. Then follows a review about modified motility assays for production of ordered motion. Here, we discuss ours and others' work with regards to making micro- and nanostructured surfaces and channels where the position and direction of movement produced by molecular motors is controlled. In this section, we consider the role of the channel size in promoting unidirectional myosin-induced motion of actin filaments. Furthermore, we consider the usefulness of surface modifications, e.g., various silanization procedures in order to promote and hinder molecular motility, respectively. Particularly, we describe our latest test system being both morphologically and chemically nanostructured giving us unsurpassed possibilities to perform functional studies as well as extremely good spatio-temporal control. Then follows a section about nanotechnological cargo transportation systems based on the actomyosin motor system. For instance, we present results of attaching fluorescent quantum dots as cargoes to the actin filaments. In this section, we also discuss the possibilities of having cargo attachment and detachment being performed on demand. Finally, we consider the usefulness of molecular motors for lab-on-a-chip applications and the requirements for incorporating these motors in commercially viable devices. In this context, the significant potential of the actomyosin motor system to overcome traditional limitations of micro- and nanofluidics is stressed.
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| 4. |
- Mansson, A, et al.
(författare)
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In vitro sliding of actin filaments labelled with single quantum dots
- 2004
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Ingår i: Biochemical and Biophysical Research Communications. - : Elsevier BV. - 1090-2104 .- 0006-291X. ; 314:2, s. 529-534
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Tidskriftsartikel (refereegranskat)abstract
- We recently refined the in vitro motility assay for studies of actomyosin function to achieve rectified myosin induced sliding of actin filaments. This paves the way, both for detailed functional studies of actomyosin and for nanotechnological applications. In the latter applications it would be desirable to use actin filaments for transportation of cargoes (e.g., enzymes) between different predetermined locations on a chip. We here describe how single quantum dot labelling of isolated actin filaments simultaneously provides handles for cargo attachment and bright and photostable fluorescence labels facilitating cargo detection and filament tracking. Labelling was achieved with preserved actomyosin function using streptavidin-coated CdSe quantum dots (Qdots). These nanocrystals have several unique physical properties and the present work describes their first use for functional studies of isolated proteins outside the cell. The results, in addition to the nanotechnology developments, open for new types of in vitro assays of isolated biomolecules. (C) 2003 Elsevier Inc. All rights reserved.
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| 5. |
- Sundberg, M, et al.
(författare)
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Silanized surfaces for in vitro studies of actomyosin function and nanotechnology applications
- 2003
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Ingår i: Analytical Biochemistry. - : Elsevier BV. - 1096-0309 .- 0003-2697. ; 323:1, s. 127-138
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Tidskriftsartikel (refereegranskat)abstract
- We have previously shown that selective heavy meromyosin (HMM) adsorption to predefined regions of nanostructured polymer resist surfaces may be used to produce a nanostructured in vitro motility assay. However, actomyosin function was of lower quality than on conventional nitrocellulose films. We have therefore studied actomyosin function on differently derivatized glass surfaces with the aim to find a substitute for the polymer resists. We have found that surfaces derivatized with trimethylchlorosilane (TMCS) were superior to all other surfaces tested, including nitrocellulose. High-quality actin filament motility was observed up to 6 days after incubation with HMM and the fraction of motile actin filaments and the velocity of smooth sliding were generally higher on TMCS than on nitrocellulose. The actomyosin function on TMCS-derivatized glass and nitrocellulose is considered in relation to roughness and hydrophobicity of these surfaces. The results suggest that TMCS is an ideal substitute for polymer resists in the nanostructured in vitro motility assay. Furthermore, TMCS derivatized glass also seems to offer several advantages over nitrocellulose for HMM adsorption in the ordinary in vitro motility assay. (C) 2003 Elsevier Inc. All rights reserved.
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