165 research outputs found

    Method for Designing Compounds and Compositions Useful for Targeting High Stoichiometric Complexes to Treat Conditions, Including Treatment of Viruses, Bacteria, and Cancers Having Acquired Drug Resistance

    Get PDF
    A method is described for the identification o f multi-subunit biocomplex drug targets. The method includes identifying a target that performs a biological function, wherein the target comprises one or more subunits, wherein a minimum number of the one or more subunits is inactivated to inhibit the biological function. The method includes selecting a drug that binds specifically to each subunit of the one or more subunits with a target probability. The method describes a relationship between inhibition efficiency of the drug and total number of the one or more subunits using a binomial distribution, wherein the inhibition efficiency comprises a probability that the delivered drug blocks the biological function. The method includes confirming empirically the relationship using an experimental target. The method includes administering the drug to the target to treat a multi-drug resistant disease, wherein the target comprises a biological complex in a mammalian subject

    Lipid Bilayer-Integrated SPP1 Connector Protein Nanopore and SPP1 Connector Protein Variants for Use as Lipid Bilayer-Integrated Nanopore

    Get PDF
    A conductive channel-containing membrane includes a membrane layer, and a SPPl connector polypeptide variant that is incorporated into the membrane layer to form an aperture through which conductance can occur when an electrical potential is applied across the membrane. A method of sensing a molecule, such as a polypeptide or nucleic acid molecule, makes use of the conductive channel- containing membrane. A method of DNA sequence makes use of the conductive channel-containing membrane

    RNA Nanoparticles and Method of Use Thereof

    Get PDF
    The presently-disclosed subject matter relates to an artificial RNA nanostructure and method of use thereof. In particular, the presently-disclosed subject matter relates to RNA nanoparticles and RNA dendrimers, and methods of disease diagnosis and treatments using the RNA nanostructure and RNA dendrimers

    Binding of pRNA to the N-terminal 14 amino acids of connector protein of bacteriophage phi29

    Get PDF
    During assembly, bacterial virus phi29 utilizes a motor to insert genomic DNA into a preformed protein shell called the procapsid. The motor contains one twelve-subunit connector with a 3.6 nm central channel for DNA transportation, six viral-encoded RNA (packaging RNA or pRNA) and a protein, gp16, with unknown stoichiometry. Recent DNA-packaging models proposed that the 5-fold procapsid vertexes and 12-fold connector (or the hexameric pRNA ring) represented a symmetry mismatch enabling production of a force to drive a rotation motor to translocate and compress DNA. There was a discrepancy regarding the location of the foothold for the pRNA. One model [C. Chen and P. Guo (1997) J. Virol., 71, 3864–3871] suggested that the foothold for pRNA was the connector and that the pRNA–connector complex was part of the rotor. However, one other model suggested that the foothold for pRNA was the 5-fold vertex of the capsid protein and that pRNA was the stator. To elucidate the mechanism of phi29 DNA packaging, it is critical to confirm whether pRNA binds to the 5-fold vertex of the capsid protein or to the 12-fold symmetrical connector. Here, we used both purified connector and purified procapsid for binding studies with in vitro transcribed pRNA. Specific binding of pRNA to the connector in the procapsid was found by photoaffinity crosslinking. Removal of the N-terminal 14 amino acids of the gp10 protein by proteolytic cleavage resulted in undetectable binding of pRNA to either the connector or the procapsid, as investigated by agarose gel electrophoresis, SDS–PAGE, sucrose gradient sedimentation and N-terminal peptide sequencing. It is therefore concluded that pRNA bound to the 12-fold symmetrical connector to form a pRNA–connector complex and that the foothold for pRNA is the connector but not the capsid protein

    Construction of a laser combiner for dual fluorescent single molecule imaging of pRNA of phi29 DNA packaging motor

    Get PDF
    A customized laser combiner was designed and constructed for dual channel single molecule imaging. The feasibility of a combiner-incorporated imaging system was demonstrated in studies of single molecule FRET. Distance rulers made of dual-labeled dsDNA were used to evaluate the system by determining the distance between one FRET pair. The results showed that the system is sensitive enough to distinguish between distances differing by two base pair and the distances calculated from FRET efficiencies are close to those documented in the literature. The single molecule FRET with the dual-color imaging system was also applied to reconstructed phi29 motor pRNA monomers. Finally, techniques for dual laser alignment and tuning of laser power for dual-color excitation are discussed

    Instrumentation and Metrology for Single RNA Counting in Biological Complexes or Nanoparticles by a Single-Molecule Dual-View System

    Get PDF
    Limited by the spatial resolution of optical microscopy, direct detection or counting of single components in biological complexes or nanoparticles is challenging, especially for RNA, which is conformationally versatile and structurally flexible. We report here the assembly of a customized single-molecule dual-viewing total internal reflection fluorescence imaging system for direct counting of RNA building blocks. The RNA molecules were labeled with a single fluorophore by in vitro transcription in the presence of a fluorescent AMP. Precise calculation of identical or mixed pRNA building blocks of one, two, three, or six copies within the bacteriophage phi29 DNA packaging motor or other complexes was demonstrated by applying a photobleaching assay and evaluated by binomial distribution. The dual-viewing system for excitation and recording at different wavelengths simultaneously will enable the differentiation of different complexes with different labels or relative motion of each labeled component in motion machines

    Programmable folding of fusion RNA \u3cem\u3ein vivo\u3c/em\u3e and \u3cem\u3ein vitro\u3c/em\u3e driven by pRNA 3WJ motif of phi29 DNA packaging motor

    Get PDF
    Misfolding and associated loss of function are common problems in constructing fusion RNA complexes due to changes in energy landscape and the nearest-neighbor principle. Here we report the incorporation and application of the pRNA-3WJ motif of the phi29 DNA packaging motor into fusion RNA with controllable and predictable folding. The motif included three discontinuous ∼18 nucleotide (nt) fragments, displayed a distinct low folding energy (Shu D et al., Nature Nanotechnology, 2011, 6:658–667), and folded spontaneously into a leading core that enabled the correct folding of other functionalities fused to the RNA complex. Three individual fragments dispersed at any location within the sequence allowed the other RNA functional modules to fold into their original structures with authentic functions, as tested by Hepatitis B virus ribozyme, siRNA, and aptamers for malachite green (MG), spinach, and streptavidin (STV). Only nine complementary nucleotides were present for any two of the three ∼18-nt fragments, but the three 9 bp branches were so powerful that they disrupted other double strands with more than 15 bp within the fusion RNA. This system enabled the production of fusion complexes harboring multiple RNA functionalities with correct folding for potential applications in biotechnology, nanomedicine and nanotechnology. We also applied this system to investigate the principles governing the folding of RNA in vivo and in vitro. Temporal production of RNA sequences during in vivo transcription caused RNA to fold into different conformations that could not be predicted with routine principles derived from in vitro studies

    RNA-Based Compositions and Adjuvants for Prophylactic and Therapeutic Treatment

    Get PDF
    The present invention is directed towards an artificial RNA nano structure comprising multiple external strands of RNA, each external strand comprising about 40-50 nucleotides; one internal strand of RNA comprising more than about 50 nucleotides; the internal strands and external strands assembled to form a triangle nanostructure, a square nanostructure, or a polygon nanostructure and a pRNA three-way junction (3WJ) motif at each vertex of the nanostructure. Such nanostructure can be provided in a composition together with an adjuvant for use in inducing the production of high affinity neutralizing antibodies or inhibitory antibodies, inducing the production of cytokines, inducing an immune response in a subject, or a combination thereof

    New Approach to Develop Ultra-High Inhibitory Drug Using the Power Function of the Stoichiometry of the Targeted Nanomachine or Biocomplex

    Get PDF
    AIMS: To find methods for potent drug development by targeting to biocomplex with high copy number. METHODS: Phi29 DNA packaging motor components with different stoichiometries were used as model to assay virion assembly with Yang Hui\u27s Triangle [Formula: see text], where Z = stoichiometry, M = drugged subunits per biocomplex, p and q are the fraction of drugged and undrugged subunits in the population. RESULTS: Inhibition efficiency follows a power function. When number of drugged subunits to block the function of the complex K = 1, the uninhibited biocomplex equals q(z), demonstrating the multiplicative effect of stoichiometry on inhibition with stoichiometry 1000 \u3e 6 \u3e 1. Complete inhibition of virus replication was found when Z = 6. CONCLUSION: Drug inhibition potency depends on the stoichiometry of the targeted components of the biocomplex or nanomachine. The inhibition effect follows a power function of the stoichiometry of the target biocomplex
    corecore