ABSTRACT
Sulfobacins A and B, novel von Willebrand factor (vWF) receptor antagonists, have been isolated from the culture broth of Chryseobacterium sp. (Flavobacterium sp.) NR 2993 by ethyl acetate extraction, and by Sephadex LH-20 and silica gel column chromatographies. The physico-chemical properties of the sulfobacins indicate that their structures are completely different from that of aurintricarboxylic acid, the one known vWF receptor antagonist. Sulfobacins A and B inhibit the binding of vWF to its receptor with IC50S of 0.47 and 2.2 microM, respectively. Sulfobacin A also inhibits ristocetin-induced agglutination in human platelets fixed with paraformaldehyde with an IC50 of 0.58 microM.
Subject(s)
Alkanesulfonic Acids/isolation & purification , Platelet Membrane Glycoproteins/antagonists & inhibitors , Receptors, Cell Surface/antagonists & inhibitors , Alkanesulfonic Acids/chemistry , Alkanesulfonic Acids/pharmacology , Animals , Cattle , Flavobacterium , Humans , Molecular StructureABSTRACT
Novel thrombin inhibitors, bacithrocins A, B and C, have been isolated from the culture broth of Bacillus laterosporus Laubach NR 2988. The structures of these inhibitors have been determined to be N-acyl-L-phenylalanyl-DL-arginal by the 2D-NMR experiments on their oxidation products and by amino acid analysis. Bacithrocin A inhibits thrombin, factor Xa and trypsin with IC50s of 48, 13 and 0.65 microM, respectively, which are similar to those of bacithrocins B and C. Bacithrocins prolong the clotting time induced by thrombin and factor Xa.
Subject(s)
Bacillus/metabolism , Dipeptides/chemistry , Thrombin/antagonists & inhibitors , Amino Acid Sequence , Chemical Phenomena , Chemistry, Physical , Dipeptides/isolation & purification , Dipeptides/pharmacology , Factor Xa Inhibitors , Fermentation , Magnetic Resonance Spectroscopy , Molecular Sequence Data , Molecular Structure , Papain/antagonists & inhibitors , Spectrometry, Mass, Fast Atom Bombardment , Trypsin InhibitorsSubject(s)
Antifungal Agents/biosynthesis , Antifungal Agents/isolation & purification , Bacillus cereus/chemistry , Bacillus cereus/metabolism , Aminobutyrates/chemistry , Aminobutyrates/isolation & purification , Aminobutyrates/metabolism , Antifungal Agents/chemistry , Chemical Phenomena , Chemistry, Physical , Fermentation , Magnetic Resonance SpectroscopyABSTRACT
Random amplified polymorphic DNA (RAPD) analysis was evaluated for the selection and elimination of bacterial strains used in microbial screening. For this pilot study we used eight bacterial strains producing fragin and two Pseudomonas fragi strains, which are often isolated during the screening. A dendrogram constructed by the statistical analysis using parsimony, PAUP, based on the band patterns of RAPD with primer R28 was in good correlation with the results of DNA-DNA hybridization, HPLC analysis of metabolites, and conventional morphological and physiological characterization. RAPD was also applicable to a wide range of bacteria. This rapid selection system by RAPD was a very useful tool for excluding similar bacterial isolates encountered during screening.
Subject(s)
Bacteria/classification , DNA, Bacterial/classification , Microbial Sensitivity Tests/methods , Polymerase Chain Reaction , Chromatography, High Pressure Liquid , DNA, Bacterial/metabolism , Electrophoresis , Pilot Projects , Random AllocationABSTRACT
Streptomyces filipinensis NR 0484 produced a new DNA gyrase inhibitor, cyclothialidine. It showed potent activity against DNA gyrases from Escherichia coli and Micrococcus luteus.
Subject(s)
Heterocyclic Compounds/isolation & purification , Heterocyclic Compounds/pharmacology , Peptides, Cyclic , Pyrroles/isolation & purification , Pyrroles/pharmacology , Streptomyces/metabolism , Topoisomerase II Inhibitors , Animals , Cattle , Escherichia coli/enzymology , Fermentation , Microbial Sensitivity Tests , Micrococcus luteus/enzymologyABSTRACT
The optimal reaction conditions for the determination of DNA-homology in Streptomyces species were established in the presence of formamide using S1 nuclease. The melting temperature of Streptomyces DNA was 90 degrees C in 0.42 M NaCl containing 20% formamide in which the denaturation was completed by boiling for 5 minutes. In the S1 reaction mixture consisting of 5 U of S1 nuclease, 0.168 M NaCl, 1 mM ZnSO4 and 8% formamide at pH 4.8, single-stranded DNA was hydrolyzed by more than 98%, while the hydrolysis of double-stranded DNA was less than 3%. From the analysis of homoduplex formation, the C0t1/2 was found at 20 hours, when a mixture of unlabeled DNA and index DNA was used at a ratio of 500:1.
