18 results on '"Zähner, H."'
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2. The carboxylate type siderophore rhizoferrin and its analogs produced by directed fermentation
- Author
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Drechsel, H., Tschierske, M., Thieken, A., Jung, G., Zähner, H., and Winkelmann, G.
- Published
- 1995
- Full Text
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3. Antioxidant properties of desferrioxamine E, a new hydroxamate antioxidant
- Author
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Shimoni, E., Ampel, M., Zähner, H., and Neeman, I.
- Published
- 1998
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4. Buchbesprechungen
- Author
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Trümper, M., Flechtner, H. -J., Walter, W., Backenstoss, G., van Calker, J., Krauch, C. H., Bruch, W., Breusch, F. L., Jørgensen, C. K., Weitramp, H., Determann, H., Kortüm, G., Łüttge, U., Bayreuther, K., Koch, Meinrad A., Zähner, H., and Wickler, W.
- Published
- 1968
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5. Identification of Streptomyces olivaceus Tü 2353 genes involved in the production of the polyketide elloramycin
- Author
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Decker, H., primary, Rohr, J., additional, Motamedi, H., additional, Zähner, H., additional, and Hutchinson, C.R., additional
- Published
- 1995
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6. Konstitution von Fusigen und dessen Abbau zu Δ2-Anhydromevalonsäurelaction.
- Author
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Diekmann, H. and Zähner, H.
- Subjects
- *
FERMENTATION , *AMINO acids , *FLUIDS , *HYDROCHLORIC acid , *LACTONES , *CHROMATOGRAPHIC analysis , *ELECTROPHORESIS - Abstract
Alkaline degradation of fusigen, a sideramine from fungi, yields the known monohydroxamic acid fusarinine. L-Ornithine and cis-5-hydroxy-3-methylpentenoic-2-acid occur in fusigen in equal amounts, and ornithine is the only amino acid. Amino group(s) with pK 7,1, but no free carboxyl group can be found in fusigen. The calculated equivalent weight is 280, which again points to fusarinine as a structural subunit. By acetylation of fusigen three products are obtained, which can be separated by electrophoresis or chromatography. The titration data of the partially acetylated fusigen and the molecular weight estimation by vapour pressure osmometry of the desferriform of the fully acetylated fusigen show that fusigen is a trimeric fusarinine. These data together with those obtained from IR- and NMR-absorption spectra lead to the proposed structure: three fusarinine molecules are esterified head-to-tail to build a 36-membered ring. The quantitative estimation of all hydroxamic acids in the culture fluid of Fusarium cubense from the 2nd to the 9th day of fermentation and structural studies on some of these compounds revealed the spontaneous degradation of fusigen by ring opening and sequential split-off of fusarinine units. An analogous degradation pathway starts from N-acetyl-fusigen. The Δ2-anhydromevalonic lactone, found in the cultures of several fungi, seems to stem from the degradation of fusarinine. The total yield of Δ2-anhydromevalonic lactone can be increased severalfold by treatment of the culture fluid with hydrochloric acid prior to extraction. [ABSTRACT FROM AUTHOR]
- Published
- 1967
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7. Phosphorylation of streptozotocin during uptake via the phosphoenolpyruvate: sugar phosphotransferase system in Escherichia coli
- Author
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Ammer, J, Brennenstuhl, M, Schindler, P, Höltje, J V, and Zähner, H
- Abstract
Mutants of Escherichia coli K-12, Staphylococcus aureus, and Bacillus subtilis defective in the general components (enzyme I, or HPr, or both) of the phosphoenolpyruvate:sugar phosphotransferase system are shown to be resistant to the antibiotic streptozotocin. It is shown here, employing 32P-labeled phosphoenolpyruvate, that wild-type cells of E. coli phosphorylate streptozotocin, whereas with a phosphotransferase system-defective mutant of E. coli the drug is recovered in an unaltered, free form. The internal accumulation of streptozotocin at the steady-state level was about 70 times that of the concentration in the external medium. The antibacterial action of streptozotocin, as well as the uptake of the drug, was inhibited by N-acetyl-D-glucosamine. The uptake of the antibiotic was extremely sensitive to p-chloromercuribenzoate. It is concluded that streptozotocin is taken up by E. coli via the phosphoenolpyruvate:sugar phosphotransferase system and consequently accumulates in the cell at first as streptozotocin-phosphate.
- Published
- 1979
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8. Kirromycin, an inhibitor of the 30 S ribosomal subunits function
- Author
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Wolf, H., Zähner, H., and Nierhaus, K.
- Published
- 1972
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9. Purification of yersiniabactin: a siderophore and possible virulence factor of Yersinia enterocolitica.
- Author
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Haag H, Hantke K, Drechsel H, Stojiljkovic I, Jung G, and Zähner H
- Subjects
- Bacterial Outer Membrane Proteins metabolism, Bacteriocins isolation & purification, Bacteriocins metabolism, Biological Transport, Active, Fermentation, Iron metabolism, Iron Chelating Agents isolation & purification, Iron Chelating Agents metabolism, Molecular Weight, Siderophores metabolism, Virulence, Yersinia enterocolitica growth & development, Yersinia enterocolitica pathogenicity, Bacterial Outer Membrane Proteins isolation & purification, Siderophores isolation & purification, Yersinia enterocolitica metabolism
- Abstract
HPLC analysis revealed that Yersinia enterocolitica WA-C produced two substances under iron-limiting conditions one of which was identified as 2,3-dihydroxybenzoyl-L-serine. The other compound had iron-complexing activity and was called yersiniabactin. The fur mutant H1852 was shown to produce yersiniabactin constitutively in an iron-independent manner. Yersiniabactin was isolated by ethyl acetate extraction from the spent medium of H1852, size-fractionation chromatography and preparative HPLC. A catechol function was demonstrated with different chemical assays and by UV-visible spectroscopy. The molecular mass of yersiniabactin was determined to be 482 Da. Purified yersiniabactin stimulated growth of Y. enterocolitica and Escherichia coli phi under iron-limiting conditions and apparently served as an iron carrier. Transport of 55Fe-yersiniabactin was TonB-dependent, indicating a receptor-mediated uptake across the outer membrane. A pesticin-resistant mutant missing the receptor protein FyuA was unable to transport and use yersiniabactin as a siderophore.
- Published
- 1993
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10. Structure-activity relationships of the nikkomycins.
- Author
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Decker H, Zähner H, Heitsch H, König WA, and Fiedler HP
- Subjects
- Anti-Bacterial Agents metabolism, Anti-Bacterial Agents pharmacology, Antifungal Agents metabolism, Antifungal Agents pharmacology, Biological Transport, Active physiology, Chromatography, High Pressure Liquid, Coprinus drug effects, Coprinus metabolism, Endopeptidases metabolism, Kinetics, Protein Conformation, Saccharomycetales drug effects, Structure-Activity Relationship, Aminoglycosides, Anti-Bacterial Agents chemistry, Antifungal Agents chemistry, Chitin Synthase antagonists & inhibitors, Coprinus enzymology, Saccharomycetales metabolism
- Abstract
The structure-activity relationships of different nikkomycins were studied to evaluate the structural requirements for a potent chitin synthase inhibitor. We investigated the transport of the nikkomycins via the peptide transport system of the yeast Yarrowia lipolytica and determined the kinetic parameters for nikkomycin Z uptake [Km = 24 microM, Vmax = 2.2 nmol min-1 (mg dry wt)-1]. We demonstrated that the beta-methyl group of the N-terminal amino acid of dipeptide nikkomycins protects the molecule against peptidase activity in crude cell-extracts of different fungi. Furthermore, the relationship between inhibition constants for chitin synthase, transport of the nikkomycins via the peptide transport system, susceptibility to degradation by cellular proteases and whole-cell activity of the nikkomycins are discussed.
- Published
- 1991
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11. Staphyloferrin A: a structurally new siderophore from staphylococci.
- Author
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Konetschny-Rapp S, Jung G, Meiwes J, and Zähner H
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- Amino Acids analysis, Chromatography, High Pressure Liquid, Chromatography, Thin Layer, Circular Dichroism, Culture Media analysis, Magnetic Resonance Spectroscopy, Molecular Structure, Ornithine isolation & purification, Stereoisomerism, Citrates isolation & purification, Ferric Compounds isolation & purification, Ornithine analogs & derivatives, Staphylococcus analysis
- Abstract
Two ferric ion-binding compounds, designated staphyloferrin A and B, were detected in the culture filtrates of staphylococci grown under iron-deficient conditions. Staphyloferrin A was isolated from cultures of Staphylococcus hyicus DSM 20459. The structural elucidation of this highly hydrophilic, acid-labile compound revealed a novel siderophore, N2,N5-di-(1-oxo-3-hydroxy-3,4-dicarboxybutyl)-D-ornithine, which consists of one ornithine and two citric acid residues linked by two amide bonds. The two citric acid components of staphyloferrin A provide two tridentate pendant ligands, comprising of a beta-hydroxy, beta-carboxy-substituted carboxylic acid derivative, for octahedral metal chelation. The CD spectrum of the staphyloferrin A ferric complex indicates a predominant A configuration about the ferric ion center. The uptake of ferric staphyloferrin A by S. hyicus obeys Michaelis-Menten kinetics (Km = 0.246 microM; vmax = 82 pmol.mg-1.min-1), indicating active transport of this siderophore. The staphyloferrin A transport system is different from that of the ferrioxamines as shown by an antagonism test. Production of staphyloferrin A is strongly iron-dependent and is stimulated by supplementation of the medium with either D- or L-ornithine. DL-[5-14C]ornithine was incorporated into staphyloferrin A, demonstrating that ornithine is an intermediate in staphyloferrin A biosynthesis.
- Published
- 1990
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12. On the transport of tripeptide antibiotics in bacteria.
- Author
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Diddens H, Zähner H, Kraas E, Göhring W, and Jung G
- Subjects
- Anti-Bacterial Agents pharmacology, Biological Transport, Cell Survival drug effects, Diffusion, Escherichia coli drug effects, Fourier Analysis, Glutamate-Ammonia Ligase antagonists & inhibitors, Magnetic Resonance Spectroscopy, Oligopeptides chemical synthesis, Oligopeptides pharmacology, Protein Conformation, Structure-Activity Relationship, Anti-Bacterial Agents metabolism, Escherichia coli metabolism, Oligopeptides metabolism
- Abstract
The two tripeptide antibiotics L-2-amino-4-methylphosphinobutyryl-alanyl-alanyl-alanine (L-phosphinothricyl-alanyl-alanine) and L-(N5-phosphono)methionine-S-sulfoximinyl-alanyl-alanine, both inhibitors of the glutamine synthetase, are transported into the cell of Escherichia coli K 12 via the oligopeptide transport system. The uptake by this system is proved first of all by cross-resistance with tri-L-ornithine using oligopeptide-transport-deficient mutants, and secondly by antagonism tests demonstrating competitive reversal of the action of the antibiotic by several peptides which have been shown to be transported via the oligopeptide transport system, e.g. tri-L-alanine, tetra-L-alanine, tri-L-lysine, tri-L-serine, tri-glycine, glycyl-glycyl-L-alanine and the synthetic tripeptide L-azadenyl-aminohexanoyl-alanyl-alanine. On the other hand, there is no effect on the action of the antibiotic in antagonism tests with compounds which use different transport systems, such as L-alanyl-alanine, L-lysyl-lysine, glutathione and the synthetic amino acid azaadenylaminohexanoic acid, i.e. 2-amino-6-(7-amino-3H-v-triazolo-[4,5-d]-pyrimidin-3-yl)hexanoic acid. Another inhibitor of the glutamine synthetase, L-methionine-S-dioxide (methioninesulfone) could be converted into a tripeptide form by linkage to L-alanyl-alanine analogously to the tripeptide antibiotics described above. Whereas the free L-methionine-S-dioxide seems to be transported via the methionine transport system, the tripeptide form is transported via the oligopeptide transport system. Thus, this glutamine synthetase inhibitor can be taken up by the cell via two different transport mechanisms. Our results indicate that this could provide a synergistic effect. The syntheses of the new tripeptides L-azaadenylaminohexanoyl-alanyl-alanine and L-methionine-S-dioxidyl-alanyl-alanine were performed by dicyclohexylcarbodiimide couplings of the unusual N-protected L-alpha-amino acids azaadenylaminohexanoic acid and L-methionine-S-dioxide to L-alanyl-alanine-tert-butyl ester followed by common deprotection steps. Tri-L-ornithine was synthesized without carboxyl protection via two successive couplings of hydroxybenzotriazol esters of Nalpha-butoxycarbonyl-Ndelta-benzyloxycarbonyl-L-ornithine.
- Published
- 1976
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13. Mode of action of the macrolide-type antibiotic, chlorothricin. Kinetic study of the inhibition of pyruvate carboxylase from Bacillus stearothermophilus.
- Author
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Schindler PW and Zähner H
- Subjects
- Acetyl Coenzyme A, Adenosine Triphosphate, Allosteric Regulation, Bacillus drug effects, Binding Sites, Enzyme Activation, Kinetics, Lactones pharmacology, Magnesium, Mathematics, Models, Chemical, Protein Binding, Pyruvates, Regression Analysis, Spectrophotometry, Ultraviolet, Anti-Bacterial Agents pharmacology, Bacillus enzymology, Glycosides pharmacology, Pyruvate Carboxylase antagonists & inhibitors
- Published
- 1973
- Full Text
- View/download PDF
14. Gallidermin: a new lanthionine-containing polypeptide antibiotic.
- Author
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Kellner R, Jung G, Hörner T, Zähner H, Schnell N, Entian KD, and Götz F
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- Alanine analysis, Amino Acid Sequence, Bacteriocins, Chromatography, High Pressure Liquid, Chromatography, Ion Exchange, Gas Chromatography-Mass Spectrometry, Microbial Sensitivity Tests, Molecular Sequence Data, Peptides, Cyclic isolation & purification, Peptides, Cyclic pharmacology, Staphylococcus metabolism, Sulfides, Alanine analogs & derivatives, Anti-Bacterial Agents isolation & purification, Anti-Bacterial Agents pharmacology, Peptides
- Abstract
Gallidermin is a new member of the class of lanthionine-containing peptide antibiotics, which are summarized under the common name lantibiotics. The lantibiotic gallidermin is produced by Staphylococcus gallinarum (F16/P57) Tü3928, and it exhibits activities against the Propionibacteria, involved in acne disease. Gallidermin differs from the recently discovered tetracyclic 21-residue peptide antibiotic epidermin only in a Leu/Ile exchange in position 6. The isolation procedures for gallidermin included adsorption directly from the culture broth, ion-exchange chromatography of the amphiphilic and basic polypeptide followed by desalting, and final purification by reversed-phase HPLC. The structural elucidation of the polypeptide containing four thioether bridges involved mainly a combination of automated gas-phase sequencing, thermospray liquid chromatography/mass spectrometry and fast-atom-bombardment mass spectrometry.
- Published
- 1988
- Full Text
- View/download PDF
15. Epidermin: sequencing of a heterodetic tetracyclic 21-peptide amide antibiotic.
- Author
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Allgaier H, Jung G, Werner RG, Schneider U, and Zähner H
- Subjects
- Amino Acid Sequence, Amino Acids analysis, Bacteriocins, Buffers, Chromatography, Gas, Chromatography, High Pressure Liquid, Chromatography, Thin Layer, Hydrolysis, Oxidation-Reduction, Peptide Fragments analysis, Peptides, Cyclic isolation & purification, Spectrum Analysis, Trypsin, Anti-Bacterial Agents isolation & purification, Peptides
- Abstract
Epidermin is a large peptide antibiotic, which is synthesized in the ribosome via a precursor protein, followed by enzymatic modifications. It was isolated from the culture filtrate of Staphylococcus epidermidis Tü 3298 by adsorption on Amberlite XAD-8. The basic heneicosapeptide amide was chromatographed on Sephadex LH-20 and purified to homogeneity via multiplicative counter-current distributions in one acidic and one neutral system. Tryptic digestion gave the soluble N-terminal fragment epidermin-(1-13)-peptide (P1) and the insoluble C-terminal fragment 2-oxobutyryl-epidermin-(15-21)-peptide amide (P2), each possessing two sulfide ring systems. The heterodetic rings consisted of meso-lanthionine and (2S,3S, 6R)-3-methyllanthionine (P1), meso-lanthionine and C-terminally the new amino acid S-(2-aminovinyl)-D-cysteine (P2). The complex sequence was elucidated via a combination of desulfurization with Raney nickel, enzymatic and acidolytic degradations, gas-phase sequencing, fast-atom bombardment and field-desorption mass spectrometry and NMR spectroscopy.
- Published
- 1986
- Full Text
- View/download PDF
16. Prepeptide sequence of epidermin, a ribosomally synthesized antibiotic with four sulphide-rings.
- Author
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Schnell N, Entian KD, Schneider U, Götz F, Zähner H, Kellner R, and Jung G
- Subjects
- Amino Acid Sequence, Bacteriocins, Base Sequence, DNA Restriction Enzymes, Molecular Sequence Data, Peptides, Cyclic genetics, Protein Conformation, Staphylococcus epidermidis genetics, Anti-Bacterial Agents, Genes, Genes, Bacterial, Peptides
- Abstract
The genetic basis for the biosynthesis of large polypeptide antibiotics such as nisin has not been explained so far. We show here that the structural gene epiA encoding the antibiotic epidermin from Staphylococcus epidermidis is located on a 54-kilobase plasmid and codes for a 52-amino-acid prepeptide, which is processed to the tetracyclic 21-peptide amide antibiotic. The mature sequence of epidermin corresponds to the C-terminal 22-peptide segment of pre-epidermin and contains the precursor amino acids Ser, Thr and Cys, from which the unusual amino-acid constituents are derived. The more lipophilic epidermin is cleaved at a hydrophilic turn between Arg-1 and Ile+1 from the N-terminal segment-30 to -1, which probably assumes a partially amphiphilic alpha-helix conformation. We propose that the N-terminus (-30 to -1) plays a cooperative role during modification reactions and prevents toxicity of the mature epidermin to the producing strain before the antibiotic is cleaved off and secreted.
- Published
- 1988
- Full Text
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17. [Constitution and catabolism of fusigen to delta-2-anhydromevalonic acid lactone].
- Author
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Diekmann H and Zähner H
- Subjects
- Chemical Phenomena, Chemistry, Physical, Chromatography, Paper, Electrophoresis, Fermentation, Hydrochloric Acid pharmacology, Hydrogen-Ion Concentration, Hydroxamic Acids metabolism, Macromolecular Substances, Magnetic Resonance Spectroscopy, Methylcellulose, Models, Structural, Molecular Weight, Ornithine metabolism, Stimulation, Chemical, Time Factors, Fusarium metabolism, Heterocyclic Compounds metabolism, Iron, Lactones metabolism, Mevalonic Acid metabolism
- Published
- 1967
- Full Text
- View/download PDF
18. Biogenetic amino acid antagonists.
- Author
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Nass G, Poralla K, and Zähner H
- Subjects
- Amino Acids metabolism, Anti-Bacterial Agents pharmacology, Azaserine pharmacology, Biodegradation, Environmental, Cell Membrane Permeability, Cell Physiological Phenomena, Cycloserine pharmacology, Molecular Biology, Peptide Biosynthesis, Purines biosynthesis, Streptomyces drug effects, Streptomyces metabolism, Amino Acids antagonists & inhibitors
- Published
- 1971
- Full Text
- View/download PDF
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