25 results on '"Netropsin"'
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2. A method of indirect mutant selection in Physarum polycephalum using the antibiotic netropsin
- Author
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William F. Dove and Jessica A. Gorman
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Cell Survival ,medicine.drug_class ,Antibiotics ,Mutant ,Amidines ,Physarum polycephalum ,Cycloheximide ,Guanidines ,chemistry.chemical_compound ,Genetics ,medicine ,Myxomycetes ,Pyrroles ,Selection, Genetic ,Molecular Biology ,Selection (genetic algorithm) ,biology ,fungi ,Temperature ,Drug Resistance, Microbial ,biology.organism_classification ,Temperature-sensitive mutant ,Anti-Bacterial Agents ,Penicillin ,chemistry ,Biochemistry ,Netropsin ,Mutation ,Oligopeptides ,Cell Division ,medicine.drug - Abstract
A method of indirect mutant selection, analogous to the bacterial penicillin technique, has been developed for Physarum polycephalum. The antibiotic netropsin was found to be lethal to growing but not to nongrowing (cycloheximide inhibited) myxamoebae. In reconstruction experiments, a 200 fold enrichment of cycloheximide sensitive over cycloheximide resistant cells was obtained. This technique was used to isolate temperature sensitive mutants. The mutant frequency among survivors was increased at least 40 fold by netropsin selection.
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- 1974
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3. Identification and separation of components of calf thymus DNA using a CsCl-netropsin density gradient
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Hana Votavová and Jaroslav Šponar
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Density gradient ,Satellite DNA ,viruses ,Cesium ,Thymus Gland ,Biology ,chemistry.chemical_compound ,Centrifugation, Density Gradient ,Methods ,Genetics ,Animals ,Centrifugation ,Binding site ,Binding Sites ,DNA ,Gradient centrifugation ,biology.organism_classification ,Molecular biology ,Anti-Bacterial Agents ,Drosophila melanogaster ,chemistry ,Netropsin ,Biophysics ,Cattle ,Satellite (biology) ,Peptides ,Protein Binding - Abstract
Calf thymus DNA containing satellite components of various densities was used as a model to study the effect of netropsin on the density of DNA in a CsCl gradient. The binding of netropsin resulted in a decrease in density which depended upon the quantity of netropsin added and on the average composition of the DNA. Differences in density of DNA components were higher in CsCl - netropsin gradients than in simple CsCl gradients. By use of netropsin a main band and four satellite bands could be differentiated in calf thymus DNA. Satellite DNA's were isolated using preparativeCsCl - netropsin gradient centrifugation and were characterised by density and homogeneity in native and in reassociated state. Two of the satellite components, with densities of 1.722 and 1.714 g/cm minus 3, are probably of homogenous sequence, the other two components of densities 1.709 and 1.705 g/cm minus 3 appear to be heterogeneous.
- Published
- 1975
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4. The compatibility of netropsin and actinomycin binding to natural deoxyribonucleic acid
- Author
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Jacquelynn E. Larson, Robert D. Wells, and Roger M. Wartell
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HMG-box ,Cell Biology ,Biology ,Ligand (biochemistry) ,Biochemistry ,chemistry.chemical_compound ,chemistry ,Netropsin ,DNA supercoil ,Titration ,Centrifugation ,Molecular Biology ,GC-content ,DNA - Abstract
The simultaneous binding of netropsin and actinomycin to four natural DNAs was studied to determine the influence of one ligand on the binding of the other. Actinomycin binds specifically to GC sites, whereas netropsin binds specifically to AT sites. Spectral titrations, thermal denaturation, and analytical buoyant density centrifugation were employed to measure the binding interference of these drugs. The binding of actinomycin to DNA was decreased by the presence of netropsin. Increasing the GC content of the DNA resulted in a decreased effect of netropsin on actinomycin binding. Quantitative analysis of the binding parameters indicated that netropsin and actinomycin can bind in close proximity along the DNA chain. Supercoiled DNA gave the same result as linear DNA. These results imply that DNA can absorb alterations in conformation within a short distance.
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- 1975
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5. Basic polypeptides as histone models: Circular dichroism of complexes of model polypeptides with DNA
- Author
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Karel Bláha, Ivo Frič, and Jaroslav Šponar
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Circular dichroism ,Macromolecular Substances ,Protein Conformation ,Stereochemistry ,Biophysics ,Biochemistry ,Histones ,chemistry.chemical_compound ,Molecule ,Centrifugation ,Proflavine ,Binding Sites ,biology ,Circular Dichroism ,Organic Chemistry ,DNA ,Molecular Weight ,Kinetics ,Crystallography ,Histone ,chemistry ,Netropsin ,Dactinomycin ,biology.protein ,Nucleic Acid Conformation ,Spectrophotometry, Ultraviolet ,Peptides ,Protein Binding - Abstract
Circular dichroism (CD) was used to study the complexes of DNA (in 0.15M NaCl) with two polypcptides considered as models of the histonc molecules. CD spectra in the region of DNA absorption were studied with respect to the concentration used for annealing and to the molecular weight and composition of the DNA used. The properties of supernatants after centrifugation of aggregated complexes were examined. The effect of selectively bound antibiotics (actinomycin D and netropsin) on CD spectra of complexes was investigated. The induced CD of proflavine molecules bound to DNA in the various complexes was also studied. It was concluded that changes in the CD spectra of DNA in complexes with the polypeptides are due to the formation of chiral superstructures, even if some conformational changes of DNA molecules themselves may also be decisive in some cases. The superstructure is affected by the composition of DNA. the role of (G + C) rich segments being particularly important.
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- 1975
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6. Netropsin
- Author
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Robert D. Wells, Jacquelynn E. Larson, and Roger M. Wartell
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Stereochemistry ,Base pair ,Lexitropsin ,Cell Biology ,Biology ,Biochemistry ,Nucleic acid thermodynamics ,chemistry.chemical_compound ,chemistry ,Netropsin ,Adenine nucleotide ,DNA supercoil ,Binding site ,Molecular Biology ,DNA - Abstract
The binding of netropsin to 31 different natural and biosynthetic DNAs, DNA-RNA hybrids, and RNAs was studied in order to delineate the nucleic acid structural features necessary for binding. The measurements employed were spectral titrations, analytical density gradient centrifugation, thermal denaturation, equilibrium dialysis, and inhibition of in vitro replication and in vitro transcription. The major conclusions are: (a) in 0.1 m or higher salt concentrations, netropsin has a marked specificity for DNAs which contain A-T (or I-C) pairs. It binds tightly to two DNAs which contain only A-T pairs and to two DNAs which contain only I-C pairs. However, no measurable binding was found for two DNAs which contain only G-C pairs. (b) Netropsin's inability to bind to G-C paired regions is a consequence of the 2-amino group of guanine. (c) Netropsin is specific for duplex DNA; no binding was observed to five single-stranded DNAs, three helical RNAs, or two of the three DNA-RNA hybrids studied. (d) Netropsin binds to DNA by a nonintercalating mechanism, since it does not cause unwinding of supercoiled DNA. (e) Netropsin inhibits in vitro DNA and RNA synthesis by binding to the template or to the primer, or to both. (f) The closest distance between bound netropsin molecules is three base pairs. A molecular model for netropsin binding in the minor groove of DNA is proposed.
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- 1974
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7. Reversal of netropsin inhibition of growth in Escherichia coli
- Author
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Walter A. Zygmunt
- Subjects
chemistry.chemical_compound ,chemistry ,Biochemistry ,Netropsin ,Biophysics ,medicine ,Cell Biology ,medicine.disease_cause ,Molecular Biology ,Escherichia coli - Published
- 1961
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8. Stability and dissociation of the DNA complexes with distamycin A and netropsin in the presence of organic solvents, urea and high salt concentration
- Author
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Gerhard Luck and Christoph Zimmer
- Subjects
Circular dichroism ,Hot Temperature ,Chemical Phenomena ,Inorganic chemistry ,Amidines ,Cesium ,Thymus Gland ,Lithium ,Nucleic Acid Denaturation ,Guanidines ,Biochemistry, Genetics and Molecular Biology (miscellaneous) ,London dispersion force ,Dissociation (chemistry) ,Hydrophobic effect ,Glycols ,chemistry.chemical_compound ,Chlorides ,Drug Stability ,Polymer chemistry ,Animals ,Urea ,Dimethyl Sulfoxide ,Pyrroles ,Tromethamine ,Edetic Acid ,Oligopeptide ,Perchlorates ,Hydrogen bond ,Circular Dichroism ,Methanol ,Osmolar Concentration ,DNA ,Anti-Bacterial Agents ,Chemistry ,chemistry ,Netropsin ,Cattle ,Spectrophotometry, Ultraviolet ,Oligopeptides - Abstract
Stability and dissociation of the DNA-distamycin A and DNA-netropsin complex in the presence of organic solvents, high salt and urea concentrations were investigated by ultraviolet absorption and circular dichroism measurements. The results show that the oligopeptide complexes are effectively disorganized by glycol or by hydrophobic bond breaking agents such as 7 M LiCl and 7.2 M NaClO4. However, the dissociation is not complete as shown for the DNA-distamycin A complex. Urea together with 2 M LiCl was found to be effective in the complete disorganization of the DNA-netropsin complex while in the case of distamycin A complex formation is still observable. It is considered that hydrogen bonding, hydrophobic interactions and dispersion forces are contributing factors, besides electrostatic interactions, in maintaining the DNA-oligopeptide complexes.
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- 1972
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9. Adenosine thymidine cluster-specific elongation and stiffening of DNA induced by the oligopeptide antibiotic netropsin
- Author
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Karl-Ernst Reinert
- Subjects
Adenosine ,Base pair ,Stereochemistry ,Peptide Chain Elongation, Translational ,Guanidines ,chemistry.chemical_compound ,Structural Biology ,Animals ,Molecule ,Pyrroles ,skin and connective tissue diseases ,Molecular Biology ,Persistence length ,Binding Sites ,Molecular mass ,Viscosity ,Chemistry ,DNA ,Anti-Bacterial Agents ,Molecular Weight ,Netropsin ,Biophysics ,Nucleic Acid Conformation ,Cattle ,sense organs ,Elongation ,Thymidine - Abstract
Conformationsl changes of DNA induced by netropsin binding have been studied by way of viscosity measurements at different DNA molecular weights. On the basis of equations derived in the Appendix for semi-rigid polymers and specialized for DNA at standard conditions, the viscosity changes are quantitatively interpreted in terms of changes of contour length and persistence length. Whereas the stiffening per bound netropsin molecule is relatively independent of the degree of binding, the elongation per one netropsin molecule bound decreases from approximately 1.5 A to zero at nearly 4 netropsin molecules/100 base pairs. A.T clusters are the sites most responsible for netropsin-induced conformationsl changes, as follows from former viscosity measurements carried out at different A + T contents. A possible role of similar conformational changes in specificity and selectivity of DNA-protein interaction is discussed.
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- 1972
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10. STUDIES ON THE STREPTOMYCES ANTIBIOTICS EFFECTIVE AGAINST INFLUENZA VIRUS, 4 TH REPORT
- Author
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On Anzai
- Subjects
Infectivity ,medicine.drug_class ,Antibiotics ,General Medicine ,Growth curve (biology) ,Biology ,biology.organism_classification ,Virology ,Newcastle disease ,Virus ,Microbiology ,chemistry.chemical_compound ,Chorioallantoic membrane ,Tissue culture ,chemistry ,Netropsin ,medicine - Abstract
As the preliminary study, growth characteristics of four viruses, i.e. influenza A (FMI), influenza B (Lee), Hemagglutinating virus of Japan (HVJ, Fushimi) and NewCastle disease virus (46-9674) have been examined in the tissue culture system using a piece of chorioallantoic membrane removed from 15-day old chick embryos as the host tissue. Among the four viruses tested, HVJ showed a characteristic growth curve when compared to the other three, i.e. long latent period for the cycle growth. The tissue culture system employed was also discussed with regard to its sensitivity of estimating alive virus particles, when compared to the egg infectivity titrations. In general, the former technic was more insensitive when compared to the latter in detecting particles and the difference lying between there two methods was most remarkable with HVJ.In the culture system described above myxoviromycin, two different kinds of streptothricins, sinanomycin (netropsin) and G-72 (chartreucin) were tested for their activity to inhibit the virus growth. When the per cent inhibition was plotted on the ordinate against the log concentration of any drug on the abscissa, characteristic inhibition curve was obtained with each antibiotics. However, in order to inhibit the growth of four viruses, the concentration required with each antibiotics was almost in the same order. With higher inoculum size in the tissue culture system described above, higher concentration of myxoviromycin was necessary to inhibit the growth. However, the fact was not the case with the remaining antibiotics.
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- 1958
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11. Netropsin, a New Antibiotic Produced by a Streptomyces
- Author
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F. X. Murphy, A. C. Finlay, F. A. Hochstein, and B. A. Sobin
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biology ,medicine.drug_class ,Stereochemistry ,Antibiotics ,General Chemistry ,biology.organism_classification ,Biochemistry ,Streptomyces ,Catalysis ,chemistry.chemical_compound ,Colloid and Surface Chemistry ,chemistry ,Netropsin ,medicine - Published
- 1951
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12. Structural Studies on the Antibiotic Netropsin
- Author
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Irving C. Kogon, A. D. G. Powell, Dwain M. White, and Eugene E. Van Tamelen
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chemistry.chemical_compound ,Colloid and Surface Chemistry ,chemistry ,medicine.drug_class ,Netropsin ,Stereochemistry ,Antibiotics ,medicine ,General Chemistry ,Biochemistry ,Catalysis - Published
- 1956
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13. Observations on Antiviral Activity of Netropsin
- Author
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Howard E. Skipper, Frank M. Schabel, R. W. Brockman, and Laster Wr
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Inoculation ,medicine.drug_class ,Therapeutic effect ,Antibiotics ,Netropsin ,Vaccinia virus ,Biology ,medicine.disease ,Streptomyces netropsis ,Antiviral Agents ,Virology ,General Biochemistry, Genetics and Molecular Biology ,Anti-Bacterial Agents ,chemistry.chemical_compound ,chemistry ,Vaccinia ,medicine ,Western equine encephalomyelitis ,Antibiotics, Antitubercular ,Encephalitis ,Pneumonitis - Abstract
SummaryNetropsin, an antibiotic from culture nitrates of Streptomyces netropsis, has marked therapeutic effect on experimental vaccinial infections (WR strain) in intracerebrally inoculated mice. It is ineffective against infections in mice with the viruses of feline pneumonitis, influenza, Western equine encephalomyelitis, and poliomyelitis.
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- 1953
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14. Selective inhibition of sporulation of Bacillus subtilis by netropsin
- Author
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Roy H. Doi, Gerald R. Keilman, and Betty Tanimoto
- Subjects
Transcription, Genetic ,medicine.drug_class ,Antibiotics ,Biophysics ,Bacillus subtilis ,Biology ,Selective inhibition ,Biochemistry ,Guanidines ,Microbiology ,chemistry.chemical_compound ,medicine ,Pyrroles ,Molecular Biology ,Gene ,Volume concentration ,chemistry.chemical_classification ,Spores, Bacterial ,Cell Biology ,biology.organism_classification ,Spore ,Anti-Bacterial Agents ,RNA, Bacterial ,Enzyme ,chemistry ,Netropsin ,Peptides ,Cell Division ,Peptide Hydrolases - Abstract
At low concentrations, the basic-polypeptide antibiotic, netropsin, did not inhibit growth, over-all RNA synthesis, replication of phage Oe, or synthesis of some catabolite-repressed enzymes in Bacillus subtilis 168. Cells developed normally until t2 of sporulation, but no refractile spores were formed in the presence of the antibiotic. The selective inhibition of sporulation by netropsin may be related to the base composition or sequence of some sporulation specific genes.
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- 1975
15. Effects of the Antibiotics Netropsin and Distamycin A on the Structure and Function of Nucleic Acids
- Author
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Christoph Zimmer
- Subjects
chemistry.chemical_compound ,Nucleic Acid Denaturation ,chemistry ,Biochemistry ,Netropsin ,Lexitropsin ,Nucleic acid ,Biophysics ,Biology ,Binding site ,DNA ,DNA Nucleotidyltransferases ,Chromatin - Abstract
Publisher Summary This chapter describes that the oligopeptides netropsin and distamycin A are bound to (dA.dT) rich regions of DNA through hydrogen bonding and van der Waals forces representing probably strong binding reactions. The abundance of (dG.dC) pairs gives rise to a weak type of binding as a result of lower hydrogen-bonding efficiency, and thus increased sensitivity to ionic environment appears. Tight binding occurs without intercalation. A suggestion for a possible hydrogen-bonding scheme of the netropsin DNA complex is presented in the chapter. Full understanding of the process of interaction between the oligopeptide antibiotics and DNA needs further intensive investigations. The chapter describes that the specificity and efficiency of the oligopeptide interaction seem to be strongly dependent on helical conformation. Tight binding fully explains the template inactivation of DNA in DNA-dependent DNA- and RNA-polymerase systems, but biological effects, such as antiviral activity or interference with multiplication of phage particles, are only partially explained by direct blocking of DNA. It also reviews that DNA and the exclusion of similar interactions with RNA, single stranded DNA and presumably with basic proteins imply usefulness in studies of nucleoproteins and in the elucidation of specific interactions in enzyme-DNA and repressor-operator systems. Finally, possible structural alterations may generate new applications. If it were possible to connect the netropsin-type structure with a suitable oligopeptide containing natural amino acids, one should expect novel modifications in binding properties.
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- 1975
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16. Accessibility of the minor groove of DNA in chromatin to the binding of antibiotics netropsin and distamycin A
- Author
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Alexei L. Zhuze, Alexander S. Zasedatelev, S. L. Grochovsky, G. V. Gursky, Alexander Kolchinsky, Anna F. Melnikova, and Andrei D. Mirzabekov
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Circular dichroism ,medicine.drug_class ,Lexitropsin ,Antibiotics ,Thymus Gland ,Biology ,DNA-binding protein ,Guanidines ,chemistry.chemical_compound ,Structure-Activity Relationship ,Genetics ,medicine ,Animals ,Pyrroles ,Molecular Biology ,Binding Sites ,Circular Dichroism ,Distamycins ,General Medicine ,Methylation ,DNA ,Chromatin ,Anti-Bacterial Agents ,chemistry ,Biochemistry ,Netropsin ,Chromatography, Gel ,Nucleic Acid Conformation ,Cattle ,Spectrophotometry, Ultraviolet - Abstract
The interaction of the antibiotics distamycin A, distamycin analogue and netropsin with chromatin of calf thymus has been studied by circular dichroism measurements and by gel filtration. The minor groove of DNA in chromatin is accessible by 83–89% to the binding of these antibiotics as compared with that of free DNA. The present results combined with our data on the methylation of chromatin with dimethylsulphate [3] strongly suggest that the minor groove of DNA in chromatin is not occupied by chromatin proteins.
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- 1975
17. The B to A transition of DNA in solution
- Author
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L. E. Minchenkova, Maxim D. Frank-Kamenetskii, A. K. Schyolkina, Valery I. Ivanov, and E. E. Minyat
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Circular dichroism ,Guanine ,Stereochemistry ,Base pair ,Cesium ,Lithium ,Guanidines ,Ion ,chemistry.chemical_compound ,Cytosine ,Structural Biology ,Animals ,Magnesium ,Pyrroles ,Guanidine ,Molecular Biology ,Binding Sites ,Ethanol ,Circular Dichroism ,digestive, oral, and skin physiology ,Sodium ,Temperature ,DNA ,Anti-Bacterial Agents ,Solutions ,Crystallography ,chemistry ,Models, Chemical ,Netropsin ,Dactinomycin ,Nucleic Acid Conformation ,Ising model ,Calcium ,Cattle - Abstract
The B to Ā transition of DNA in water-ethanol solutions has been studied by circular dichroism. The transition is reversible and co-operative and occurs within a narrow concentration range of alcohol (70 to 80% ethanol). The value of water activity within this interval corresponds to the value of the relative humidity for the B to Ā transition in DNA fibres. An increase in Na+ concentration results in a shift of the transition curve to lower ethanol concentrations. By contrast, Li+, Cs+, guanidine+, Mg2+, and Ca2+ ions stabilize the 5 form. The B α A equilibrium is not influenced by temperature. The B to Ā transition may have only a slight dependence (if any) on G + C content, since the transition width is the same for the heterogeneous calf thymus DNA and the homogeneous bacterial and phage DNA. Hence, in the B to Ā transition DNA behaves as a “single-stranded” (the strands are not separated) homopolymer. This allows one to apply the simplest variant of the Ising model to the description of the B to Ā transition. On the basis of data obtained in the presence of the antibiotic netropsin, which stabilizes the B form, we estimated the co-operativity length, ν0 = 20 base pairs, and the free energy difference of the Ā and B states in water, FA − FB ~ 1 kcal/mol.
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- 1974
18. Distamycin A and Netropsin
- Author
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Fred E. Hahn
- Subjects
chemistry.chemical_compound ,Chemistry ,Netropsin ,Stereochemistry ,Chemical structure ,Lexitropsin ,Molecule ,Total synthesis ,Chromophore ,Optical rotatory dispersion ,Cotton effect - Abstract
Distamycin A is a fermentation product of Streptomyces distallicus (Arcamone et al., 1958). Its chemical structure (Fig. 1) has been determined by organic chemical methods and confirmed by total synthesis (Arcamone et al., 1964; Penco et al., 1967). The compound has a distinctive ultraviolet absorption spectrum (Arcamone et al. 1964) and is optically non-active (DiMarco et al, 1962; Arcamone et al., 1964). The absence of intrinsic Cotton effects indicates that the n-methyl-pyrrole chromophores of the antibiotic molecule in solution are not asymmetrically perturbed but more precise information on the configuration of distamycin A in physiological solution is lacking. Experimental studies of the molecular pharmacology of distamycin A are hampered by the instability of the antibiotic.
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- 1975
- Full Text
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19. Conformation dependent binding of netropsin and distamycin to DNA and DNA model polymers
- Author
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Ch. Zimmer, G. Luck, Hans Triebel, and M. Waring
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chemistry.chemical_classification ,Circular dichroism ,Binding Sites ,Hydrogen bond ,Stereochemistry ,Lexitropsin ,Circular Dichroism ,Distamycins ,Netropsin ,DNA ,Biology ,In Vitro Techniques ,chemistry.chemical_compound ,Polydeoxyribonucleotides ,chemistry ,Biochemistry ,Helix ,Genetics ,Animals ,Nucleic Acid Conformation ,Nucleotide ,Cattle ,Binding site - Abstract
The binding of the antibiotics netropsin and distamycin A to DNA has been studied by thermal melting, CD and sedimentation analysis. Netropsin binds strongly at antibiotic/nucleotide ratios up to at least 0.05. CD spectra obtained using DNA model polymers reveal that netropsin binds tightly to poly (dA) . poly (dT), poly (dA-dT) . poly(dA-dT) and poly (dI-dC) . poly (dI-dC) but poorly, if at all, to poly (dG) . poly (dC). Binding curves obtained with calf thymus DNA reveal one netropsin-binding site per 6.0 nucleotides (K(a)=2.9 . 10(5) M(-1)); corresponding values for distamycin A are one site per 6.1 nucleotides with K(a)= 11.6 . 10(5) M(-1). Binding sites apparently involve predominantly A.T-rich sequences whose specific conformation determines their high affinity for the two antibiotics. It is suggested that the binding is stabilized primarily by hydrogen bonding and electrostatic interactions probably in the narrow groove of the DNA helix, but without intercalation. Any local structural deformation of the helix does not involve unwinding greater than approximately 3 degrees per bound antibiotic molecule.
- Published
- 1974
20. Binding of analogues of the antibiotics distamycin A and netropsin to native DNA. Effect of chomophore systems and basic residues of the oligopeptides on thermal stability, conformation and template activity of the DNA complexes
- Author
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Gerhard Luck, Heinz Thrum, Christoph Zimmeer, and Christian Pitra
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Circular dichroism ,Hot Temperature ,Chemical Phenomena ,Stereochemistry ,Ultraviolet Rays ,Lexitropsin ,Amidines ,Nucleic Acid Denaturation ,Biochemistry ,Guanidines ,chemistry.chemical_compound ,Drug Stability ,Pyrroles ,Oligopeptide ,Cell-Free System ,Chemistry ,Circular Dichroism ,Spectrum Analysis ,Phosphorus Isotopes ,DNA ,Templates, Genetic ,Chromophore ,Anti-Bacterial Agents ,Netropsin ,Nucleic Acid Conformation ,RNA ,Chirality (chemistry) ,Peptides ,Protein Binding - Abstract
Binding effects of DNA with two distamycin A analogues containing four and five 1-methyl-pyrrole residues (distamycin A contains three of these residues) and with a degradation product of netropsin have been investigated by ultraviolet absorbance, melting and circular dichroism measurements. Increasing numbers of the methylpyrrole groups (3 to 5) enhance the thermal stability of the oligopeptide complex. On the other hand elimination of the basic groups of the netropsin molecule decreases the melting temperature of the oligopeptide · DNA complex enormously. The circular dichroism spectrum of DNA is also less affected by the degradation product compared to netropsin. Circular dichroism spectra of the complexes exhibit a pronounced band at the longer wavelength region and indicate an increasing chirality in the complex with increasing number of chromophores of the oligopeptides. From the results it is concluded that electrostatic attraction of the oligopeptides by interaction of the propionamidino and guanidino groups with the negative phosphate sites of DNA is important for the formation of the complex. However, non-ionic forces, which have been discussed earlier, seem to be involved and may be attributed to the chromophore residues oriented in the helical grooves. The different binding tendency of the oligopeptides with DNA is discussed together with the biological activity of the oligopeptides.
- Published
- 1972
21. Influence of netropsin and distamycin A on the secondary structure and template activity of DNA
- Author
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Bernd Puschendorf, Hans Grunicke, Christoph Zimmer, Harry Venner, and Prakash Chandra
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Hot Temperature ,Ultraviolet Rays ,Lexitropsin ,In Vitro Techniques ,Biochemistry ,Nucleic acid secondary structure ,Absorption ,Phosphates ,chemistry.chemical_compound ,Escherichia coli ,Animals ,Pyrroles ,Carcinoma, Ehrlich Tumor ,Protein secondary structure ,Oligopeptide ,Binding Sites ,Chemistry ,Spectrum Analysis ,Temperature ,RNA Nucleotidyltransferases ,DNA ,Streptomyces ,Chromatin ,Nucleoprotein ,Anti-Bacterial Agents ,Netropsin ,Biophysics ,RNA ,Cattle ,Peptides - Abstract
The action of netropsin and distamycin A on the DNA secondary structure and on the template properties of DNA in the DNA-and RNA-polymerase systems have been studied. Ultraviolet absorption measurements indicate characteristic hypochromic effects for the DNA-antibiotic complexes due to binding of netropsin and distamycin A to DNA. These are accompanied by the appearance of an absorption peak beyond 320 nm. This ultraviolet absorption maximum depends on the (A+T) content of DNA and disappears upon heat denaturation. These results together with earlier observations indicate an A and T specificity of the binding of the oligopeptides netropsin and distamycin A. As demonstrated by absorbance-temperature measurements netropsin increases considerably the thermal stability of DNA. Drastic changes can even be obtained with ratios below 5 moles netropsin per 100 DNA phosphate groups. The antibiotic dependent increase in the melting temperature is more pronounced for the DNA · netropsin than for the DNA · distamycin A complex. The structure of denatured DNA is also affected markedly by both antibiotics. From the results it is concluded that binding of netropsin and distamycin A to DNA is the result of their affinity to double-helical and base stacked regions. Comparison of the effect of these antibiotics on DNA-and RNA-synthesis in vitro shows that both netropsin and distamycin A inhibit the DNA- and RNA-polymerase reactions. In both systems the template activity of native as well as of denatured DNA is affected by these antibiotics. Using chromatin of Ehrlich ascites tumor cells as template it could be shown, that the nucleoprotein complex is as sensitive to the action of distamycin A as pure DNA.
- Published
- 1971
22. Interaction of the oligopeptide antibiotics netropsin and distamycin A with nucleic acids
- Author
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G. Löber, U. Wähnert, Karl-Ernst Reinert, Ch. Zimmer, H. Thrum, and G. Luck
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DNA, Bacterial ,Protein Denaturation ,Hot Temperature ,Stereochemistry ,Ultraviolet Rays ,Lexitropsin ,Thymus Gland ,Antiviral Agents ,Models, Biological ,chemistry.chemical_compound ,RNA, Transfer ,Structural Biology ,Nucleic Acids ,Magnesium ,Pyrroles ,Binding site ,Molecular Biology ,Optical rotatory dispersion ,Binding Sites ,Viscosity ,RNA ,DNA ,Anti-Bacterial Agents ,Optical Rotatory Dispersion ,chemistry ,Netropsin ,Ionic strength ,RNA, Ribosomal ,Spectrophotometry ,DNA, Viral ,Nucleic acid ,Peptides - Abstract
The influence of the oligopeptide antibiotics netropsin and distamycin A on the structure of DNA, ribosomal RNA and transfer RNA have been investigated by thermal melting, ultraviolet spectrophotometry, viscosity and optical rotatory dispersion measurements. The binding of both oligopeptides is accompanied by a pronounced stabilization of the DNA helix structure which persists up to high ionic strength (1 m -NaClO4) while RNA is relatively unaffected at comparable ionic conditions. A · T-rich DNA exhibits a much higher increase of the melting temperature than A · T-poor DNA: in the presence of netropsin ΔTm was found to be 33 deg.C for 71 mole % A + T compared to 8 deg.C for 28 mole % A + T. A pronounced increase in the viscosity of DNA-netropsin complexes occurs up to 0.05 netropsin/ DNA-P depending on the A + T-content of the DNA. On the other hand In η rel c decreases immediately upon addition of distamycin A up to 0.05 distamycin A/DNA-P. Drastic changes were also observed in the shape of the optical rotatory dispersion curve of DNA in the presence of netropsin or distamycin A beyond 250 nm associated with an optically induced transition in the regions of 315 and 330 nm. RNA does not show a similar effect. The ultraviolet-absorption maximum of the oligopeptides is displaced towards longer wavelength on interaction with DNA. The results clearly demonstrate that the DNA structure is very sensitive to the binding of both oligopeptides while RNA is relatively insensitive. The DNA-antibiotic complexes formed are very stable due to the high affinity and specificity of netropsin and distamycin A for A · T-rich domains. Two classes of binding sites are discussed for the netropsin interaction with DNA. Distamycin A apparently seems to form intra- and intermolecular cross-links between DNA helices. The binding of netropsin and distamycin A to DNA causes a perturbation of the DNA B-conformation. The results are interpreted in terms of a contribution of the chromophore system of netropsin and distamycin A to the pronounced conformational changes observed. A tentative model for the interaction of these oligopeptides with DNA is briefly discussed.
- Published
- 1971
23. (dA.dT)-dependent inactivation of the DNA template properties by interaction with netropsin and distamycin A
- Author
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G. Luck, U. Wähnert, Ch. Pitra, and Ch. Zimmer
- Subjects
Hot Temperature ,Stereochemistry ,Lexitropsin ,Deoxyribonucleotides ,Polynucleotides ,Peptide ,Biology ,Micrococcus ,chemistry.chemical_compound ,Drug Stability ,RNA polymerase ,Escherichia coli ,Genetics ,Thymine Nucleotides ,chemistry.chemical_classification ,Binding Sites ,Adenine Nucleotides ,Hydrogen bond ,Circular Dichroism ,Osmolar Concentration ,DNA ,DNA-Directed RNA Polymerases ,Templates, Genetic ,Streptomyces ,Anti-Bacterial Agents ,Kinetics ,chemistry ,Biochemistry ,Netropsin ,DNA Nucleotidyltransferases ,Nucleic acid ,Peptides ,Thymidine ,Protein Binding - Abstract
The inhibitory effect of the polypeptide antibiotics netropsin and distamycin A on DNA dependent nucleic acid synthesis has been shown to be related to the base composition of the template DNA. A number of natural DNA's of quite different dA·dT content as well as poly (dI-dC)·poly (dI-dC), poly (dA-dT)·poly (dA-dT), poly (dA) · poly (dT) and poly (dG)·poly(dC) has been studied as templates in DNA and in part in RNA polymerase reaction. The highest binding efficiency of netropsin existing for (dA·dT)-containing DNA polymers and the less pronounced interaction with the (dI·dC)-containing polymer shown by the melting and CD spectral behaviour of the complexes are entirely reflected in the template inactivation. The same is evident for distamycin A. However, in contrast to netropsin the antibiotic distamycin A exhibits some binding tendency to poly (dG)·poly (dC). Binding effects of a netropsin derivative to DNA and (dA·dT)-containing polymers suggest the importance of hydrogen bonds of the peptide groups in the complex formation.
- Published
- 1975
- Full Text
- View/download PDF
24. Observations on antiviral activity of netropsin.
- Author
-
SCHABEL FM Jr, LASTER WR Jr, BROCKMAN RW, and SKIPPER HE
- Subjects
- Anti-Bacterial Agents pharmacology, Antibiotics, Antitubercular, Antiviral Agents, Netropsin, Vaccinia, Vaccinia virus
- Published
- 1953
- Full Text
- View/download PDF
25. ON THE STRUCTURE OF NETROPSIN.
- Author
-
NAKAMURA S, YONEHARA H, and UMEZAWA H
- Subjects
- Anti-Bacterial Agents, Chemical Phenomena, Chemistry, Netropsin
- Published
- 1964
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