Existence of DNA in yeast microbodies

1978 ◽  
Vol 36 (2) ◽  
pp. 232-233
Author(s):  
Masako Osumi ◽  
Misuzu Nagano ◽  
Hiroko Kazama
Keyword(s):  
Catalase Activity ◽  
Buoyant Density ◽  
Model System ◽  
Contour Length ◽  
Native State ◽  
Normal Alkane ◽  
Remarkable Increase ◽  
Dna Molecule ◽  
Mitochondrial Dnas

We have found that microbodies appeared profusely together with a remarkable increase in catalase activity in normal alkane-grown cells of hydrocarbon-utilizing Candida yeasts, and that the microbodies multiplied by division in these cells. These features of Candida yeasts seem to provide a useful model system for studies on the biogenesis of the microbody. Subsequently, we have succeeded in isolation of Candida microbodies in an apparently native state, as judged biochemically and morphologically. The presence of DNA in the purified microbody fraction thus obtained was proved by the diphenylamine method. DNA molecule of about 15 urn in contour length was released from an isolated microbody. The physicochemical analyses of the microbody DNA revealed that its buoyant density differed from nuclear and mitochondrial DNAs. All these results lead us to the possibility that there is a novel type of DNA in microbodies.

Influence of Nanochannel Inlet Structure Upon DNA Capture Ratio

2011 ◽  
Author(s):  
Jiahao Wu ◽  
Hong Wang ◽  
Jinsoo Kim ◽  
Freddy Murphy ◽  
Steven A. Soper ◽  
...  
Keyword(s):  
Real Time ◽  
Persistence Length ◽  
Contour Length ◽  
Dna Molecules ◽  
Channel Diameter ◽  
Dna Molecule ◽  
Capture Ratio ◽  
Sequence Variations ◽  
Dna Capture ◽  
Dna Chain

DNA molecule will be stretched to its near full contour length inside a nanochannel when the channel diameter is less than the DNA persistence length.1–3 It provides the possibility of real time lab-free-analysis of analysis, such as screening of sequence variations of DNA molecules.3 The key process for this nanochannel-based analysis is to drive DNA molecule electrophoretically through the nanochannel and read out the information of the DNA chain while it is passing the channel.2, 3

On the mycophage of Penicillium chrysogenum

1973 ◽  
Vol 19 (1) ◽  
pp. 97-103 ◽  
Author(s):  
C. H. Nash ◽  
R. J. Douthart ◽  
L. F. Ellis ◽  
R. M. Van Frank ◽  
J. P. Burnett ◽  
...  
Keyword(s):  
Ribonucleic Acid ◽  
Penicillium Chrysogenum ◽  
Thermal Denaturation ◽  
Buoyant Density ◽  
Ion Concentration ◽  
Contour Length ◽  
Viral Dsrna ◽  
Viral Particles ◽  
Profile Characteristic ◽  
Isopycnic Centrifugation

A mycovirus has been purified from mycelia of Penicillium chrysogenum by isopycnic centrifugation in sucrose and in CsCl. Viral particles band with a buoyant density of 1.20 in sucrose and 1.38 in CsCl. Particles have icosohedral symmetry, are 35 nm in diameter, and have an absorption profile characteristic of nucleoprotein. One enzymatic activity, RNA polymerase, is associated with the purified mycophage. Nucleic acid extracted from purified virus has a buoyant density in CS2SO4 of 1.61, a molar extinction coefficient of εp (258 nm) of 7200, a s20, w of 13.0, and a pattern of circular dichroism characteristic of double-helical ribonucleic acid. Molecules of this double-stranded ribonucleic acid (dsRNA), examined by electron microscopy, have a mean contour length of 0.86 μm which corresponds to a molecular weight of about 2.0 × 106 daltons. This dsRNA is resolved further by acrylamide gel electrophoresis into three closely spaced bands. Thermal denaturation of the viral dsRNA is dependent on ionic strength and gives a linear relationship with the negative logarithm of the sodium ion concentration.

scholarly journals Non-additive effects of changing the cytochrome P450 ensemble: incorporation of CYP2E1 into human liver microsomes and its impact on CYP1A2

2019 ◽  
Author(s):  
Nadezhda Y. Davydova ◽  
Bikash Dangi ◽  
Marc A. Maldonado ◽  
Nikita E. Vavilov ◽  
Victor G. Zgoda ◽  
...  
Keyword(s):  
Cytochrome P450 ◽  
Human Liver ◽  
Liver Microsomes ◽  
Model System ◽  
Human Liver Microsomes ◽  
Specific Substrate ◽  
Additive Effects ◽  
Main Route ◽  
Remarkable Increase ◽  
Functional Differences

AbstractThe aim of this study is to investigate the ability of ethanol-inducible CYP2E1 to interact with other cytochrome P450 species and affect the metabolism of their substrates. As a model system we used CYP2E1-enriched microsomes obtained by incorporation of purified CYP2E1 protein into HLM. Using the method based on homo-FRET in homo-oligomers of CYP2E1 labeled with BODIPY 577/618 maleimide we demonstrated that the interactions of CYP2E1 with microsomes result in dissociation of the protein homo-oligomers. The finding that this effect is much better pronounced in HLM as compared to the microsomes containing no P450 proteins indicates the formation of mixed oligomers of CYP2E1 with other P450 species that takes place in expense of dissociation of the homo-oligomers.Incorporation of CYP2E1 into HLM results in a multifold increase in the rate of metabolism of CYP2E1-specific substratesp-Nitrophenol (pNP) and Chlorzaxozone (CLZ). The rate of their oxidation remains proportional to the amount of incorporated CYP2E1 up to the content of 0.3-0.4 nmol/mg protein (or about 50% CYP2E1 in the P450 pool). These results demonstrate that the incorporated CYP2E1 becomes a fully-functional member of the P450 ensemble and do not exhibit any detectable functional differences with the endogenous CYP2E1 in HLM.Enrichment of HLM with CYP2E1 results in a pronounced alteration of the metabolism of 7-etoxy-4-cyanocoumarin (CEC), the substrate of CYP2C19 and CYP1A2, that suggests an important augmentation of the involvement of CYP1A2 in its metabolism. This effect goes together with a remarkable increase in the rate of dealkylation of CYP1A2-specific substrate 7-ethoxyresorufin by CYP2E1-enriched HLM. Furthermore, probing the interactions of CYP2E1 with model microsomes (Supersomes™) containing individual P450 enzymes we found that CYP2E1 efficiently interacts with CYP1A2, but lacks any ability to form complexes with CYP2C19. This finding goes inline with CYP2E1-induced redirection of the main route of CEC metabolism from CYP2C19 to CYP1A2.

Mitochondrial DNA from 4-Cell Stages of Ascaris Lumbricoides

1974 ◽  
Vol 16 (3) ◽  
pp. 593-601
Author(s):  
H. TOBLER ◽  
C. GUT
Keyword(s):  
Electron Microscopy ◽  
Mitochondrial Dna ◽  
Ascaris Lumbricoides ◽  
Buoyant Density ◽  
Contour Length ◽  
Cell Stage ◽  
Replicative Intermediates ◽  
Dna Amounts

Mitochondrial DNA (mtDNA) has been isolated from 4-cell stages of Ascaris lumbricoides. This DNA amounts to about 40% of the total quantity of 4-cell-stage DNA. Its buoyant density in neutral CsCl gradients is 1.686 g cm-3. Electron microscopy of mtDNA demonstrated the presence of circular molecules with an average contour length of 4.64 µm. About 15% of these molecules are supercoiled, covalently closed circles, whereas some 2% consist of double-forked circular molecules. The form and size of these branched molecules suggest that they are replicative intermediates.

scholarly journals Electron Microscopic Evidence for a Multimeric System of Plasmids in Fast-Growing Rhizobium Spp.

1979 ◽  
Vol 32 (6) ◽  
pp. 651 ◽  
Author(s):  
EA Schwinghamer ◽  
ES Dennis
Keyword(s):  
Size Range ◽  
Buoyant Density ◽  
Contour Length ◽  
Chromosomal Dna ◽  
Electron Microscopic ◽  
Fast Growing ◽  
Open Circular ◽  
Rhizobium Spp ◽  
Fast Growing Rhizobia ◽  
Wide Size Range

Covalently closed circular (CCC)-DNA could be isolated, by dye-buoyant density centrifugation, from l3 out of 15 strains from three species of fast-growing rhizobia. The plasmid band was also present in ineffective mutants and non-infective mutants derived from symbiotically effective, plasmid-carrying parent strains. The buoyant density in caesium chloride was 1� 719 g/cm3 for chromosomal DNA and 1� 715-1� 716 g/cm3 for plasmid DNA in the four strains examined. Electron microscopy of the CCC-DNA from five strains revealed a wide size range of large circular molecules, with the contour length ranging from l3. 5 to c. 170 jim (mol. wt range 28 x 106-352 x 106 ). Analysis of the size distribution of open circular molecules from the five strains indicated that a multimeric series of plasmid molecules may occur in these bacteria, with an estimated mean monomer length of l3�5 jlin.

scholarly journals SINGLE STRAND-CONTAINING REPLICATING MOLECULES OF CIRCULAR MITOCHONDRIAL DNA

1973 ◽  
Vol 56 (1) ◽  
pp. 230-245 ◽  
Author(s):  
David R. Wolstenholme ◽  
Katsuro Koike ◽  
Patricia Cochran-Fouts
Keyword(s):  
Mitochondrial Dna ◽  
Single Strand ◽  
Molecular Forms ◽  
Contour Length ◽  
Chick Embryos ◽  
Single Stranded Region ◽  
Mitochondrial Dnas ◽  
Replicative Intermediates ◽  
Circular Contour ◽  
Protein Monolayer

Mitochondrial DNAs (mtDNAs) from Chang rat solid hepatomas and Novikoff rat ascites hepatomas were examined in the electron microscope after preparation by the aqueous and by the formamide protein monolayer techniques. MtDNAs from both tumors were found to include double-forked circular molecules with a form and size suggesting they were replicative intermediates. These molecules were of two classes. In molecules of one class, all three segments were apparently totally double stranded. Molecules of the second class were distinguished by the fact that one of the segments spanning the region between the forks in which replication had occurred (the daughter segments) was either totally single stranded, or contained a single-stranded region associated with one of the forks. Daughter segments of both totally double-stranded and single strand-containing replicating molecules varied in length from about 3 to about 80% of the circular contour length of the molecule. Similar classes of replicating molecules were found in mtDNA from regenerating rat liver and chick embryos, indicating them to be normal intermediates in the replication of mtDNA All of the mtDNAs examined included partially single-stranded simple (nonforked) circular molecules. A possible scheme for the replication of mtDNA is presented, based on the different molecular forms observed

Molecular Arrangement of DNA in Nucleohistone

1975 ◽  
Vol 30 (9-10) ◽  
pp. 575-585 ◽  
Author(s):  
S. Basu
Keyword(s):  
Rotational Diffusion ◽  
Linear Dichroism ◽  
Contour Length ◽  
Hydrodynamic Properties ◽  
Dna Molecule ◽  
Molecular Arrangement ◽  
Diffusion Studies ◽  
Polarization Of Fluorescence ◽  
End Distance ◽  
Total Dna

Several optical and hydrodynamic properties of purified nucleohistone have indicated that the secondary structure of DNA in nucleohistone is slightly different both from the structures of native and denatured DNA in solution. It has been suggested that while histones stabilize the overall DNA-structure they incorporate into the latter some denaturation defects. Rotational diffusion studies of acridine-orange complexes of whole and dehistonized nucleohistones have indicated that nucleohistone should contain a single continuous DNA molecule. The contour length of the DNA molecule would be about 2 to 3 times the end-to-end distance of nucleohistone. Polarized fluorescence microscopy and linear dichroism studies of whole nucleohistone have given an average estimate (about 30% of the total DNA) of oriented DNA in nucleohistone. The degree and the direction of maximum polarization of fluorescence from the dye complexes of whole and partial (i. e. partially dissociated) nucleohistones have been studied. From these studies, it is proposed that no single supercoiled arrangement of the DNA in nucleohistone is tenable. The combined results of all these studies suggest that the basic nucleohistone molecule contains coiled and extended DNA regions. The proportion of the lengths of the DNA constrained in the coiled and the extended regions is about 7:3. Only two probable models or classes have this quantitative feature of the DNA-arrangement and have been discussed.

Enzymatic and Physical Studies on the Triplex dTn∙dAn∙rUn

1973 ◽  
Vol 51 (4) ◽  
pp. 436-449 ◽  
Author(s):  
Nancy L. Murray ◽  
A. Richard Morgan
Keyword(s):  
Buoyant Density ◽  
Minor Groove ◽  
Model System ◽  
Rational Approach ◽  
Major Groove ◽  
Dna And Rna ◽  
Pancreatic Rnase ◽  
Mixing Curves ◽  
Transcription And Replication

The triplex dTn∙dAn∙rUn was studied as a model system both enzymatically and physically with a view that a rational approach for attempting to isolate triplexes from in vivo situations might emerge. The triplex was characterized by mixing curves and by its equilibrium buoyant density. In 5 mM Na phosphate, pH 7.3, for KCl concentrations below 0.4 M the triplex dissociated into dTn∙dAn + rUn, dissociation being complete at about 0.3 M KCl. If MgCl2 replaced KCl a strongly cooperative dissociation occurred at 1 mM MgCl2. Whereas with alkaline titration of dTn∙dAn∙rUn, rUn was dissociated first followed by dTn∙dAn, acidic titration resulted in the whole triplex dissociating together. Both transcription and replication of dTn∙dAn were strongly inhibited by formation of a triplex. The DNA and RNA moieties in the triplex are somewhat protected against DNase I and pancreatic RNase degradation, when compared with duplex dTn∙dAn or rUn. Spermine binds equally well to dTn∙dAn and dTn∙dAn∙rUn which is consistent with spermine binding in the minor groove and RNA in the major groove of DNA.

scholarly journals On the Internal Structure of Bacteriophage Lambda

1966 ◽  
Vol 49 (6) ◽  
pp. 171-178 ◽  
Author(s):  
A. D. Kaiser
Keyword(s):  
Electron Microscopy ◽  
Coat Protein ◽  
Internal Structure ◽  
Bacteriophage Lambda ◽  
Buoyant Density ◽  
Chelating Agent ◽  
Internal Diameter ◽  
Dna Molecule ◽  
The Core ◽  
Phage Dna

The structure of bacteriophage lambda has been studied by electron microscopy of negatively stained particles. The phage particles will eject their DNA if they are heated or dialyzed against a chelating agent. The ghost particles, so formed, have a channel running down their tails. Since the channel is not visible in normal particles, the channel may be filled with part of the DNA molecule. Up to 30% of the ghosts contain round objects about half the internal diameter of the head. The round objects, called "cores," have the same buoyant density as the coat protein. The core may be a protein spool about which the phage DNA is wound.

scholarly journals Covalently closed, circular DNA in kappa endosymbionts ofParamecium

1976 ◽  
Vol 27 (2) ◽  
pp. 161-170 ◽  
Author(s):  
Judith A. Dilts
Keyword(s):  
Density Gradient Centrifugation ◽  
Gradient Centrifugation ◽  
Buoyant Density ◽  
Bacterial Chromosome ◽  
Contour Length ◽  
Paramecium Tetraurelia ◽  
Extrachromosomal Dna ◽  
Circular Dna ◽  
Covalently Closed Circular Dna ◽  
Circular Molecule

SUMMARYCaedobacter taeniospiralis(kappa), a bacterial endosymbiont isolated fromParamecium tetraureliastock 51, contains, in addition to the bacterial chromosome, covalently closed circular DNA molecules as shown by isolation on dye-buoyant-density gradients. The closed circular molecule has a contour length of 13·75 ± 0·04 µm with a buoyant density of 1·698 g/cm3. The buoyant density of the bacterial chromosome is 1·700–1·701 g/cm3. Kappa of the 51 group isolated from stock 298 and stock 6g2,P. tetraurelia, also contain the closed circular DNA. Two forms of kappa coexist in paramecia: brights and nonbrights. Examination by density-gradient centrifugation of the DNA of brights and nonbrights shows the extrachromosomal DNA to be associated mainly with brights. It is suggested that the extrachromosomal DNA might be the determinant for the refractile bodies and the helical phage-like structures found in brights.

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