Actin Filament Guidance on a Chip: Toward High-Throughput Assays and Lab-on-a-Chip Applications

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• 作者：Mark Sundberg ; Richard Bunk ; Nuria Albet-Torres ; Anders Kvennefors ; Fredrik Persson ; Lars Montelius ; Ian A. Nicholls ; Sara Ghatnekar-Nilsson ; P&auml ; r Omling ; Sven T&aring ; gerud ; Alf M&aring ; nsson
• 刊名：Langmuir
• 出版年：2006
• 出版时间：August 15, 2006
• 年：2006
• 卷：22
• 期：17
• 页码：7286 - 7295
• 全文大小：540K
• 年卷期：v.22,no.17(August 15, 2006)
• ISSN：1520-5827

文摘

Biological molecular motors that are constrained so that function is effectively limited to predefined nanosizedtracks may be used as molecular shuttles in nanotechnological applications. For these applications and in high-throughput functional assays (e.g., drug screening), it is important that the motors propel their cytoskeletal filamentsunidirectionally along the tracks with a minimal number of escape events. We here analyze the requirements forachieving this for actin filaments that are propelled by myosin II motor fragments (heavy meromyosin; HMM). First,we tested the guidance of HMM-propelled actin filaments along chemically defined borders. Here, trimethylchlorosilane(TMCS)-derivatized areas with high-quality HMM function were surrounded by SiO₂ domains where HMM did notbind actin. Guidance along the TMCS-SiO₂ border was almost 100% for filament approach angles between 0 and20ages/entities/deg.gif"> but only about 10% at approach angles near 90ages/entities/deg.gif">. A model (Clemmens, J.; Hess, H.; Lipscomb, R.; Hanein, Y.;Bohringer, K. F.; Matzke, C. M.; Bachand, G. D.; Bunker, B. C.; Vogel, V. Langmuir 2003, 19, 10967-10974)accounted for essential aspects of the data and also correctly predicted a more efficient guidance of actin filamentsthan previously shown for kinesin-propelled microtubules. Despite the efficient guidance at low approach angles,nanosized (<700 nm wide) TMCS tracks surrounded by SiO₂ were not effective in guiding actin filaments. Neitherwas there complete guidance along nanosized tracks that were surrounded by topographical barriers (walls and roofpartially covering the track) unless there was also chemically based selectivity between the tracks and surroundings.In the latter case, with dually defined tracks, there was close to 100% guidance. A combined experimental andtheoretical analysis, using tracks of the latter type, suggested that a track width of less than about 200-300 nm issufficient at a high HMM surface density to achieve unidirectional sliding of actin filaments. In accord with theseresults, we demonstrate the long-term trapping of actin filaments on a closed-loop track (width < 250 nm). The resultsare discussed in relation to lab-on-a-chip applications and nanotechnology-assisted assays of actomyosin function.