Fabrication of Massive Sheets of Single Layer Patterned Arrays Using Lipid Directed Reengineered Phi29 Motor Dodecamer

Department of Biomedical Engineering, University of Cincinnati, Cincinnati, Ohio 45221, USA.
ACS Nano (Impact Factor: 12.03). 02/2009; 3(1):100-7. DOI: 10.1021/nn800409a
Source: PubMed

ABSTRACT The bottom-up assembly of patterned arrays is an exciting and important area in current nanotechnology. Arrays can be engineered to serve as components in chips for a virtually inexhaustible list of applications ranging from disease diagnosis to ultra-high-density data storage. Phi29 motor dodecamer has been reported to form elegant multilayer tetragonal arrays. However, multilayer protein arrays are of limited use for nanotechnological applications which demand nanoreplica or coating technologies. The ability to produce a single layer array of biological structures with high replication fidelity represents a significant advance in the area of nanomimetics. In this paper, we report on the assembly of single layer sheets of reengineered phi29 motor dodecamer. A thin lipid monolayer was used to direct the assembly of massive sheets of single layer patterned arrays of the reengineered motor dodecamer. Uniform, clean and highly ordered arrays were constructed as shown by both transmission electron microscopy and atomic force microscopy imaging.

  • [Show abstract] [Hide abstract]
    ABSTRACT: The ingenious design of the bacterial virus phi29 DNA packaging nano-motor with an elegant and elaborate channel has inspired its application for single molecule detection of antigen/antibody interactions. The hub of this bacterial virus nanomotor is a truncated cone-shaped connector consisting of twelve protein subunits. These subunits form a ring with a central 3.6-nm channel acting as a path for dsDNA to enter during packaging and to exit during infection. The connector has been inserted into a lipid bilayer. Herein, we reengineered an Epithelial Cell Adhesion Molecule (EpCAM) peptide into the C-terminal of nanopore as a probe to specifically detect EpCAM antibody (Ab) in nano-molar concentration at the single molecule level. The binding of Abs sequentially to each peptide probe induced step-wise blocks in current. The distinctive current signatures enabled us to analyze the docking and undocking kinetics of Ab-probe interactions and determine the Kd. The signal of EpCAM antibody can be discriminated from the background events in the presence of non-specific antibody or serum. Our results demonstrate the feasibility of generating a highly sensitive platform for detecting antibodies at extremely low concentrations in the presence of contaminants.
    ACS Nano 10/2013; 7(11). DOI:10.1021/nn404435v · 12.03 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Background Double-stranded DNA translocation is ubiquitous in living systems. Cell mitosis, bacterial binary fission, DNA replication or repair, homologous recombination, Holliday junction resolution, viral genome packaging and cell entry all involve biomotor-driven dsDNA translocation. Previously, biomotors have been primarily classified into linear and rotational motors. We recently discovered a third class of dsDNA translocation motors in Phi29 utilizing revolution mechanism without rotation. Analogically, the Earth rotates around its own axis every 24 hours, but revolves around the Sun every 365 days. Results Single-channel DNA translocation conductance assay combined with structure inspections of motor channels on bacteriophages P22, SPP1, HK97, T7, T4, Phi29, and other dsDNA translocation motors such as bacterial FtsK and eukaryotic mimiviruses or vaccinia viruses showed that revolution motor is widespread. The force generation mechanism for revolution motors is elucidated. Revolution motors can be differentiated from rotation motors by their channel size and chirality. Crystal structure inspection revealed that revolution motors commonly exhibit channel diameters larger than 3 nm, while rotation motors that rotate around one of the two separated DNA strands feature a diameter smaller than 2 nm. Phi29 revolution motor translocated double- and tetra-stranded DNA that occupied 32% and 64% of the narrowest channel cross-section, respectively, evidencing that revolution motors exhibit channel diameters significantly wider than the dsDNA. Left-handed oriented channels found in revolution motors drive the right-handed dsDNA via anti-chiral interaction, while right-handed channels observed in rotation motors drive the right-handed dsDNA via parallel threads. Tethering both the motor and the dsDNA distal-end of the revolution motor does not block DNA packaging, indicating that no rotation is required for motors of dsDNA phages, while a small-angle left-handed twist of dsDNA that is aligned with the channel could occur due to the conformational change of the phage motor channels from a left-handed configuration for DNA entry to a right-handed configuration for DNA ejection for host cell infection. Conclusions The revolution motor is widespread among biological systems, and can be distinguished from rotation motors by channel size and chirality. The revolution mechanism renders dsDNA void of coiling and torque during translocation of the lengthy helical chromosome, thus resulting in more efficient motor energy conversion.
    06/2014; 4:30. DOI:10.1186/2045-3701-4-30
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The ability of isolated bacterial cell surface layer (S-layer) protein subunits to self-assemble into protein layers on solid surfaces makes them an almost ideal biological template for sensor oriented applications. Here, we used this remarkable property of the recombinant S-layer protein of Sporosarcina ureae bacterium to display streptavidin in defined order and orientation into two dimensional, nanosized protein lattices. We show that these lattices constitute a functional biomolecular matrix by binding biotinylated quantum dots on its surface. Therefore, they have a great application potential as sensor elements.
    01/2011; DOI:10.1109/NANO.2011.6144303

Full-text (3 Sources)

Available from
May 21, 2014