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The Biochemical Journal May 19691. Chloroplasts and mitochondria were isolated by aqueous and non-aqueous cell-fractionation techniques. In a variety of higher plants the mitochondrial DNA bands in a...
1. Chloroplasts and mitochondria were isolated by aqueous and non-aqueous cell-fractionation techniques. In a variety of higher plants the mitochondrial DNA bands in a caesium chloride gradient at 1.706g.cm.(-3), whereas chloroplastal DNA has a buoyant density of 1.697g.cm.(-3). 2. In total cellular DNA of moderate molecular weight, the chloroplastal DNA is found within the Gaussian distribution of the nuclear DNA and is not resolved as a satellite. 3. Both chloroplastal DNA and mitochondrial DNA from lettuce renature rapidly. 4. The kinetic complexity of mitochondrial DNA is > 10(8) daltons. 5. Chloroplastal DNA is made up from fast and slow renaturing sequences with kinetic complexities of 3x10(6) and 1.2x10(8) daltons respectively. 6. From the discrepancy between analytical and kinetic complexity it is concluded that chloroplastal DNA is extensively reiterated.
Topics: Cell Nucleus; Centrifugation, Density Gradient; Chloroplasts; DNA; DNA, Bacterial; DNA, Viral; Densitometry; Kinetics; Methods; Microscopy, Electron; Mitochondria; Molecular Weight; Nucleic Acid Denaturation; Plant Cells; Plants; Purines; Pyrimidinones; Species Specificity; Time Factors
PubMed: 5821734
DOI: 10.1042/bj1120777 -
Analytical Sciences : the International... Aug 2019This paper describes a deoxyribonucleic-acid-sensitive electrolyte solution-gate field-effect transistor (SGFET) sensor utilizing a partial carboxyl-terminated...
This paper describes a deoxyribonucleic-acid-sensitive electrolyte solution-gate field-effect transistor (SGFET) sensor utilizing a partial carboxyl-terminated boron-doped polycrystalline diamond surface as a linker to connect a deoxyribonucleic acid (DNA) probe. A high density of carboxyl termination on the polycrystalline diamond surface that was employed as a FET channel was achieved using a vacuum ultraviolet system with oxygen gas. A single-stranded DNA probe was immobilized on the polycrystalline diamond channel via amino coupling. The current-voltage characteristics of the polycrystalline diamond SGFET sensor was examined with bias voltages within its potential voltage window. The characteristics of the drain-source current verses the drain-source voltage showed a pinch-off, a shift voltage of up to 40 mV with a coefficient of variation of 4 - 11% was obtained between hybridization and denaturation. In addition, a single nucleotide mutation of DNA sequence was selectively recognized by the shift voltage up to ca. 10 mV.
Topics: Boron; Crystallization; DNA; Diamond; Nucleic Acid Hybridization; Polymers; Solutions; Transistors, Electronic
PubMed: 31061238
DOI: 10.2116/analsci.18P520 -
Journal of Bacteriology Jun 1962Falkow, Stanley (Walter Reed Army Institute of Research, Washington D.C.), I. R. Ryman, and O. Washington. Deoxyribonucleic acid base composition of Proteus and...
Falkow, Stanley (Walter Reed Army Institute of Research, Washington D.C.), I. R. Ryman, and O. Washington. Deoxyribonucleic acid base composition of Proteus and Providence organisms. J. Bacteriol. 83:1318-1321. 1962.-Deoxyribonucleic acids (DNA) from various species of Proteus and of Providence bacteria have been examined for their guanine + cytosine (GC) content. P. vulgaris, P. mirabilis, and P. rettgeri possess essentially identical mean GC contents of 39%, and Providence DNA has a GC content of 41.5%. In marked contrast, P. morganii DNA was found to contain 50% GC. The base composition of P. morganii is only slightly lower than those observed for representatives of the Escherichia, Shigella, and Salmonella groups. Aerobacter and Serratia differ significantly from the other members of the family by their relatively high GC content. Since a minimal requirement for genetic compatibility among different species appears to be similarity of their DNA base composition, it is suggested that P. morganii is distinct genetically from the other species of Proteus as well as Providence strains. The determination of the DNA base composition of microorganisms is important for its predictive information. This information should prove of considerable value in investigating genetic and taxonomic relationships among bacteria.
Topics: Bacteria; Base Composition; DNA; DNA, Bacterial; Proteus
PubMed: 13891463
DOI: 10.1128/jb.83.6.1318-1321.1962 -
Journal of Virology Aug 1967A replicative hybrid resulting from the infection of heavy (substituted with 5-bromodeoxyuridine) bacteria with light (not substituted with 5-bromodeoxyuridine)...
A replicative hybrid resulting from the infection of heavy (substituted with 5-bromodeoxyuridine) bacteria with light (not substituted with 5-bromodeoxyuridine) radioactive bacteriophage was isolated from a CsCl density gradient. Sedimentation studies indicate that 60% of the deoxyribonucleic acid (DNA) behaves as if it were in units more than four times as large as an intact reference molecule. Under the electron microscope, hybrid molecules appeared tangled, showed puffs and loops, occupied a small area, and often had a total length twice that of mature phage. This indicates that sucrose gradient sedimentation is not applicable as a method for estimating the relative molecular size of replicative forms of DNA. After denaturation, the separated strands of hybrid were of the same size as those of reference DNA. CsCl density gradient analysis revealed no terminal covalent addition of new material to the old parental strand. The possibility of a continuous growth of the DNA molecule, either on a single-stranded level or as a double helical structure, is disproved. When chloramphenicol (CM) was added at critical times after infection, DNA synthesis continued at a constant rate. The parental label soon assumed and retained a hybrid density, despite concomitant synthesis of DNA, throughout the rest of the period of incubation in CM. The hybrid moiety, however, actively participated in replication and exchanged its partner strand for a new one; this was demonstrated by changing the density label during incubation in CM. A new enzyme synthesized shortly after infection introduced single-stranded "nicks" into the parental DNA. Since nicking can be inhibited by chloramphenicol, the responsible enzyme is not of host origin. The time of the appearance of this enzyme coincided with the onset of molecular recombination. Another enzyme, which mediates the repair of the continuity of the polynucleotide chain after recombination, appeared after recombination. If selectively inhibited by chloramphenicol, recombinant molecules remained unrepaired, and, upon denaturation, the parental fragment was liberated in pure form.
Topics: Bromodeoxyuridine; Centrifugation, Density Gradient; Chloramphenicol; Coliphages; DNA Replication; DNA, Viral; Enzyme Induction; Recombination, Genetic
PubMed: 5621474
DOI: 10.1128/JVI.1.4.758-770.1967 -
Bacteriological Reviews Sep 1968
Review
Topics: Bacterial Proteins; Centrifugation, Density Gradient; Chromatography; Coliphages; Crosses, Genetic; DNA, Bacterial; DNA, Viral; Escherichia coli; Genetics, Microbial; Mutation; Virus Replication
PubMed: 4879238
DOI: 10.1128/br.32.3.227-242.1968 -
The Journal of Biological Chemistry Apr 1963
Topics: Corrinoids; DNA; DNA, Bacterial; Glycine; Lactobacillus; Lactobacillus leichmannii; Purines; RNA; RNA, Bacterial; Vitamin B 12; Vitamins
PubMed: 14023696
DOI: No ID Found -
Journal of Bacteriology Mar 1965Smith, Robert C. (Auburn University, Auburn, Ala.), and W. D. Salmon. Effect of ethionine on the ribonucleic acid, deoxyribonucleic acid, and protein content of...
Smith, Robert C. (Auburn University, Auburn, Ala.), and W. D. Salmon. Effect of ethionine on the ribonucleic acid, deoxyribonucleic acid, and protein content of Escherichia coli. J. Bacteriol. 89:687-692. 1965.-The addition of ethionine to cultures of Escherichia coli K-12 W6, a methionine-requiring auxotroph, led to inhibition of the rate of increase in optical density when the ratio of ethionine to methionine was 200:1. When the ratio was 600:1, the increase in optical density became linear. When ethionine was substituted for methionine in the medium, the optical density of the culture increased, and there was a parallel increase in protein content. There was no cell division in these cultures. The rate of synthesis of ribonucleic acid (RNA) in a culture containing ethionine was similar to that of a culture deprived of methionine, but the synthesis of deoxyribonucleic acid in a culture with ethionine was about twice that of a culture deprived of methionine. No detectable radioactivity from ethionine-ethyl-1-C(14) was incorporated into RNA. Ethionine-ethyl-1-C(14) was readily incorporated into the protein fraction.
Topics: Amino Acids; Bacterial Proteins; Carbon Isotopes; DNA; DNA, Bacterial; Escherichia coli; Escherichia coli K12; Ethionine; Metabolism; Methionine; Pharmacology; Proteins; RNA; RNA, Bacterial; Research
PubMed: 14273646
DOI: 10.1128/jb.89.3.687-692.1965 -
International Journal of Nanomedicine 2014To explore a spatiotemporally controllable gene delivery system with high efficiency and safety, polyelectrolyte multilayer (PEM) films were constructed on titanium or...
To explore a spatiotemporally controllable gene delivery system with high efficiency and safety, polyelectrolyte multilayer (PEM) films were constructed on titanium or quartz substrates via layer-by-layer self-assembly technique by using plasmid deoxyribonucleic acid-loaded lipopolysaccharide-amine nanopolymersomes (pNPs) as polycations and hyaluronic acid (HA) as polyanions. pNPs were chosen because they have high transfection efficiency (>95%) in mesenchymal stem cells (MSCs) and induce significant angiogenesis in zebrafish in conventional bolus transfection. The assembly process of PEM films was confirmed by analyses of quartz crystal microbalance with dissipation, X-ray photoelectron spectroscopy, infrared, contact angle, and zeta potential along with atomic force microscopy observation. Quartz crystal microbalance with dissipation analysis reveals that this film grows in an exponential mode, pNPs are the main contributor to the film mass, and the film mass can be modulated in a relatively wide range (1.0-29 μg/cm(2)) by adjusting the deposition layer number. Atomic force microscopy observation shows that the assembly leads to the formation of a patterned film with three-dimensional tree-like nanostructure, where the branches are composed of beaded chains (pNP beads are strung on HA molecular chains), and the incorporated pNPs keep structure intact. In vitro release experiment shows that plasmid deoxyribonucleic acid can be gradually released from films over 14 days, and the released plasmid deoxyribonucleic acid exists in a complex form. In vitro cell experiments demonstrate that PEM films can enhance the adhesion and proliferation of MSCs and efficiently transfect MSCs in situ in vitro for at least 4 days. Our results suggest that a (pNPs/HA)n system can mediate efficient transfection in stem cells in a spatially and temporally controllable pattern, highlighting its huge potential in local gene therapy.
Topics: Animals; Cell Adhesion; Cell Proliferation; DNA; Hyaluronic Acid; Mesenchymal Stem Cells; Nanostructures; Nanotechnology; Plasmids; Rats; Rats, Sprague-Dawley; Titanium; Transfection
PubMed: 25378927
DOI: 10.2147/IJN.S70952 -
Proceedings of the National Academy of... Jul 1962
The role of deoxyribonucleic acid in ribonucleic acid synthesis. III. The inhibition of the enzymatic synthesis of ribonucleic acid and deoxyribonucleic acid by actinomycin D and proflavin.
Topics: Biochemical Phenomena; DNA; Dactinomycin; Flavins; Proflavine; RNA
PubMed: 14450185
DOI: 10.1073/pnas.48.7.1222 -
PloS One 2020A DNA (DeoxyriboNucleic Acid) algorithm is proposed to solve the job shop scheduling problem. An encoding scheme for the problem is developed and DNA computing...
A DNA (DeoxyriboNucleic Acid) algorithm is proposed to solve the job shop scheduling problem. An encoding scheme for the problem is developed and DNA computing operations are proposed for the algorithm. After an initial solution is constructed, all possible solutions are generated. DNA computing operations are then used to find an optimal schedule. The DNA algorithm is proved to have an O(n2) complexity and the length of the final strand of the optimal schedule is within appropriate range. Experiment with 58 benchmark instances show that the proposed DNA algorithm outperforms other comparative heuristics.
Topics: Algorithms; Computer Simulation; Computers; Computers, Molecular; DNA; Heuristics; Humans
PubMed: 33264317
DOI: 10.1371/journal.pone.0242083