| microbial communities in the chemocline of a hypersaline deep-sea basin (urania basin, mediterranean sea). | the urania basin is a hypersaline sulfidic brine lake at the bottom of the eastern mediterranean sea. since this basin is located at a depth of approximately 3,500 m below the sea surface, it receives only a small amount of phytoplankton organic carbon. in the present study, the bacterial assemblages at the interface between the hypersaline brine and the overlaying seawater were investigated. the sulfide concentration increased from 0 to 10 mm within a vertical interval of 5 m across the interfa ... | 2001 | 11722884 |
| characterization and description of anaeromyxobacter dehalogenans gen. nov., sp. nov., an aryl-halorespiring facultative anaerobic myxobacterium. | five strains were isolated which form a physiologically and phylogenetically coherent group of chlororespiring microorganisms and represent the first taxon in the myxobacteria capable of anaerobic growth. the strains were enriched and isolated from various soils and sediments based on their ability to grow using acetate as an electron donor and 2-chlorophenol (2-cph) as an electron acceptor. they are slender gram-negative rods with a bright red pigmentation that exhibit gliding motility and form ... | 2002 | 11823233 |
| archazolid and apicularen: novel specific v-atpase inhibitors. | v-atpases constitute a ubiquitous family of heteromultimeric, proton translocating proteins. according to their localization in a multitude of eukaryotic membranes, they energize many different transport processes. since their malfunction is correlated with various diseases in humans, the elucidation of the properties of this enzyme for the development of selective inhibitors and drugs is one of the challenges in v-atpase research. | 2005 | 16080788 |
| metabolomics approach for determining growth-specific metabolites based on fourier transform ion cyclotron resonance mass spectrometry. | fourier transform ion cyclotron resonance mass spectrometry (ft-icr/ms) is the best ms technology for obtaining exact mass measurements owing to its great resolution and accuracy, and several outstanding ft-icr/ms-based metabolomics approaches have been reported. a reliable annotation scheme is needed to deal with direct-infusion ft-icr/ms metabolic profiling. correlation analyses can help us not only uncover relations between the ions but also annotate the ions originated from identical metabol ... | 2008 | 18560811 |
| proteasome regulators: activators and inhibitors. | this mini review covers the drug discovery aspect of both proteasome activators and inhibitors. the proteasome is involved in many essential cellular functions, such as regulation of cell cycle, cell differentiation, signal transduction pathways, antigen processing for appropriate immune responses, stress signaling, inflammatory responses, and apoptosis. due to the importance of the proteasome in cellular functions, inhibition or activation of the proteasome could become a useful therapeutic str ... | 2009 | 19275603 |
| archazolid a binds to the equatorial region of the c-ring of the vacuolar h+-atpase. | the macrolactone archazolid is a novel, highly specific v-atpase inhibitor with an ic(50) value in the low nanomolar range. the binding site of archazolid is presumed to overlap with the binding site of the established plecomacrolide v-atpase inhibitors bafilomycin and concanamycin in subunit c of the membrane-integral v(o) complex. using a semi-synthetic derivative of archazolid for photoaffinity labeling of the v(1)v(o) holoenzyme we confirmed binding of archazolid to the v(o) subunit c. for t ... | 2010 | 20884613 |
| fatty acid-related phylogeny of myxobacteria as an approach to discover polyunsaturated omega-3/6 fatty acids. | in an analysis of 47 aerobic myxobacterial strains, representing 19 genera in suborders cystobacterineae, nannocystineae, sorangiineae, and a novel isolate, "aetherobacter" sbsr008, an enormously diverse array of fatty acids (fas) was found. the distribution of straight-chain fatty acids (scfas) and branched-chain fatty acids (bcfas) supports the reported clustering of strains in the phylogenetic tree based on 16s rrna genes. this finding additionally allows the prediction and assignment of the ... | 2011 | 21317327 |
| isolation and identification of myxobacteria from saline-alkaline soils in xinjiang, china. | fifty-eight terrestrial and salt-tolerant myxobacteria were isolated from the saline-alkaline soils collected from xinjiang, china. based on the morphologies and the 16s rrna gene sequences, these isolates were assigned into 6 genera, myxococcus, cystobacter, corallococcus, sorangium, nannocystis and polyangium. all the strains grew better with 1% nacl than without nacl. some myxococcus strains were able to grow at 2% nacl concentration, suggesting that these strains may be particular type of te ... | 2013 | 23936436 |
| approach to analyze the diversity of myxobacteria in soil by semi-nested pcr-denaturing gradient gel electrophoresis (dgge) based on taxon-specific gene. | the genotypic diversity of insoluble macromolecules degraded myxobacteria, provided an opportunity to discover new bacterial resources and find new ecological functions. in this study, we developed a semi-nested-pcr-denaturing gradient gel electrophoresis (dgge) strategy to determine the presence and genotypic diversity of myxobacteria in soil. after two rounds of pcr with myxobacteria-specific primers, an 194 bp fragment of mgla, a key gene involved in gliding motility, suitable for dgge was ob ... | 2014 | 25280065 |
| comparison of myxobacterial diversity and evaluation of isolation success in two niches: kiritimati island and german compost. | myxobacteria harbor an enormous potential for new bioactive secondary metabolites and therefore the isolation of in particular new groups is of great interest. the diversity of myxobacteria present in two ecological habitats, namely sand from kiritimati island and german compost, was evaluated by both cultivation-based and cultivation-independent methods. phylogenetic analyses of the strains in comparison with 16s rrna gene sequences from cultured and uncultured material in genbank revealed a gr ... | 2016 | 26669488 |
| comparison of myxobacterial diversity and evaluation of isolation success in two niches: kiritimati island and german compost. | myxobacteria harbor an enormous potential for new bioactive secondary metabolites and therefore the isolation of in particular new groups is of great interest. the diversity of myxobacteria present in two ecological habitats, namely sand from kiritimati island and german compost, was evaluated by both cultivation-based and cultivation-independent methods. phylogenetic analyses of the strains in comparison with 16s rrna gene sequences from cultured and uncultured material in genbank revealed a gr ... | 2016 | 26669488 |
| total synthesis and biological evaluation of tubulysin u, tubulysin v, and their analogues. | a stereoselective total synthesis of the cytotoxic natural products tubulysin u, tubulysin v, and its unnatural epimer epi-tubulysin v, is reported. simplified analogues containing n,n-dimethyl-d-alanine as a replacement for the n-terminal n-me-pipecolinic acid residue of the tubulysins are also disclosed. biological evaluation of these natural products and analogues provided key information with regard to structural and stereochemical requirements for antiproliferative activity and tubulin poly ... | 2009 | 19102699 |
| pretubulysin: from hypothetical biosynthetic intermediate to potential lead in tumor therapy. | pretubulysin is a natural product that is found in strains of myxobacteria in only minute amounts. it represents the first enzyme-free intermediate in the biosynthesis of tubulysins and undergoes post-assembly acylation and oxidation reactions. pretubulysin inhibits the growth of cultured mammalian cells, as do tubulysins, which are already in advanced preclinical development as anticancer and antiangiogenic agents. the mechanism of action of this highly potent compound class involves the depoly ... | 2012 | 22616003 |
| a robust pcr primer design platform applied to the detection of acidobacteria group 1 in soil. | environmental biosurveillance and microbial ecology studies use pcr-based assays to detect and quantify microbial taxa and gene sequences within a complex background of microorganisms. however, the fragmentary nature and growing quantity of dna-sequence data make group-specific assay design challenging. we solved this problem by developing a software platform that enables pcr-assay design at an unprecedented scale. as a demonstration, we developed quantitative pcr assays for a globally widesprea ... | 2012 | 22434885 |
| development of proteasome inhibitors as therapeutic drugs. | the proteasome is a multi-unit enzyme complex found in the cytoplasm and nucleus of all eukaryotic cells and is responsible for degradation of unneeded or damaged intracellular proteins by proteolysis, a chemical reaction that breaks peptide bonds. proteasome inhibition presents a promising approach to cancer therapy by targeting the proteasome function in tumor cells. delineating the success of bortezomib in the treatment of multiple myeloma and mantle cell lymphoma, this review explores variou ... | 2012 | 23338480 |
| identification of myxobacteria-derived hiv inhibitors by a high-throughput two-step infectivity assay. | drug-resistance and therapy failure due to drug-drug interactions are the main challenges in current treatment against human immunodeficiency virus (hiv) infection. as such, there is a continuous need for the development of new and more potent anti-hiv drugs. here we established a high-throughput screen based on the highly permissive tzm-bl cell line to identify novel hiv inhibitors. the assay allows discriminating compounds acting on early and/or late steps of the hiv replication cycle. | 2013 | 24063434 |
| mode of cell death induction by pharmacological vacuolar h+-atpase (v-atpase) inhibition. | the vacuolar h(+)-atpase (v-atpase), a multisubunit proton pump, has come into focus as an attractive target in cancer invasion. however, little is known about the role of v-atpase in cell death, and especially the underlying mechanisms remain mostly unknown. we used the myxobacterial macrolide archazolid b, a potent inhibitor of the v-atpase, as an experimental drug as well as a chemical tool to decipher v-atpase-related cell death signaling. we found that archazolid induced apoptosis in highly ... | 2013 | 23168408 |
| mode of cell death induction by pharmacological vacuolar h+-atpase (v-atpase) inhibition. | the vacuolar h(+)-atpase (v-atpase), a multisubunit proton pump, has come into focus as an attractive target in cancer invasion. however, little is known about the role of v-atpase in cell death, and especially the underlying mechanisms remain mostly unknown. we used the myxobacterial macrolide archazolid b, a potent inhibitor of the v-atpase, as an experimental drug as well as a chemical tool to decipher v-atpase-related cell death signaling. we found that archazolid induced apoptosis in highly ... | 2013 | 23168408 |
| machine learning estimates of natural product conformational energies. | machine learning has been used for estimation of potential energy surfaces to speed up molecular dynamics simulations of small systems. we demonstrate that this approach is feasible for significantly larger, structurally complex molecules, taking the natural product archazolid a, a potent inhibitor of vacuolar-type atpase, from the myxobacterium archangium gephyra as an example. our model estimates energies of new conformations by exploiting information from previous calculations via gaussian pr ... | 2014 | 24453952 |
| azaphilones from an acid mine extremophile strain of a pleurostomophora sp. | an extremophilic fungus identified as a pleurostomophora sp. was isolated from the berkeley pit, an acid mine waste lake. when grown in liquid culture, the fungus produced berkchaetoazaphilones a-c (1, 2, and 5), the red pigment berkchaetorubramine (6), and the known compound 4-(hydroxymethyl)quinoline. these compounds were evaluated as inhibitors of matrix metalloproteinase-3, caspase-1, and proinflammatory cytokine production in induced thp-1 cells. berkchaetoazaphilone b (2) inhibited il-1β, ... | 2015 | 26641525 |
| anti-leukemic effects of the v-atpase inhibitor archazolid a. | prognosis for patients suffering from t-all is still very poor and new strategies for t-all treatment are urgently needed. our study shows potent anti-leukemic effects of the myxobacterial v-atpase inhibitor archazolid a. archazolid a reduced growth and potently induced death of leukemic cell lines and human leukemic samples. by inhibiting lysosomal acidification, archazolid a blocked activation of the notch pathway, however, this was not the mechanism of v-atpase inhibition relevant for cell de ... | 2015 | 26496038 |
| 2-(3'-indolyl)-n-arylthiazole-4-carboxamides: synthesis and evaluation of antibacterial and anticancer activities. | a new series of 2-(3'-indolyl)-n-arylthiazole-4-carboxamides 17a-p has been designed and synthesized. initial reaction of readily available thioamides 15 with bromopyruvic acid under refluxing conditions produced different thiazole carboxylic acids 16 which upon coupling with arylamines by using edci·hcl and hobt afforded diverse arylthiazole-4-carboxamides 17a-p in 78-87% yields. antibacterial activity evaluation against gram-positive and gram-negative bacterial strains led to compounds 17i-k a ... | 2015 | 26298501 |
| α,β-dehydroamino acids in naturally occurring peptides. | α,β-dehydroamino acids are naturally occurring non-coded amino acids, found primarily in peptides. the review focuses on the type of α,β-dehydroamino acids, the structure of dehydropeptides, the source of their origin and bioactivity. dehydropeptides are isolated primarily from bacteria and less often from fungi, marine invertebrates or even higher plants. they reveal mainly antibiotic, antifungal, antitumour, and phytotoxic activity. more than 60 different structures were classified, which ofte ... | 2015 | 25323736 |
| α,β-dehydroamino acids in naturally occurring peptides. | α,β-dehydroamino acids are naturally occurring non-coded amino acids, found primarily in peptides. the review focuses on the type of α,β-dehydroamino acids, the structure of dehydropeptides, the source of their origin and bioactivity. dehydropeptides are isolated primarily from bacteria and less often from fungi, marine invertebrates or even higher plants. they reveal mainly antibiotic, antifungal, antitumour, and phytotoxic activity. more than 60 different structures were classified, which ofte ... | 2015 | 25323736 |
| stereoselective access to tubuphenylalanine and tubuvaline: improved mn-mediated radical additions and assembly of a tubulysin tetrapeptide analog. | synthesis of tubuphenylalanine and tubuvaline (tuv), α-substituted γ-amino acid building blocks for tubulysin family of antimitotic compounds, has been improved using a radical addition reaction in the presence of unprotected hydroxyl functionality. the key carbon-carbon bond construction entails stereoselective mn-mediated photolytic additions of alkyl iodides to the c=n bond of chiral n-acylhydrazones, and generates the chiral amines in high yield with complete stereocontrol. reductive n-n bon ... | 2016 | 26883395 |
| highlights of marine invertebrate-derived biosynthetic products: their biomedical potential and possible production by microbial associants. | coral reefs are among the most productive marine ecosystems and are the source of a large group of structurally unique biosynthetic products. annual reviews of marine natural products continue to illustrate that the most prolific source of bioactive compounds consist of coral reef invertebrates-sponges, ascidians, mollusks, and bryozoans. this account examines recent milestone developments pertaining to compounds from invertebrates designated as therapeutic leads for biomedical discovery. the fo ... | 2011 | 21835627 |
| identification of novel genomic islands in liverpool epidemic strain of pseudomonas aeruginosa using segmentation and clustering. | pseudomonas aeruginosa is an opportunistic pathogen implicated in a myriad of infections and a leading pathogen responsible for mortality in patients with cystic fibrosis (cf). horizontal transfers of genes among the microorganisms living within cf patients have led to highly virulent and multi-drug resistant strains such as the liverpool epidemic strain of p. aeruginosa, namely the lesb58 strain that has the propensity to acquire virulence and antibiotic resistance genes. often these genes are ... | 2016 | 27536294 |
| life in cellulose houses: symbiotic bacterial biosynthesis of ascidian drugs and drug leads. | ascidians (tunicates; sea squirts) are sources of diverse, bioactive natural products, one of which is an approved drug and many of which are potent drug leads. it has been shown that symbiotic bacteria living with ascidians produce some of the bioactive compounds isolated from whole animals, and indirect evidence strongly implicates symbiotic bacteria in the synthesis of many others. however, for the majority the producing organism has not been identified. in cases where a symbiotic origin has ... | 2010 | 21050742 |
| screening of small molecules affecting mammalian p-body assembly uncovers links with diverse intracellular processes and organelle physiology. | processing bodies (p-bodies) are cytoplasmatic mrnp granules containing non-translating mrnas and proteins from the mrna decay and silencing machineries. the mechanism of p-body assembly has been typically addressed by depleting p-body components. here we apply a complementary approach and establish an automated cell-based assay platform to screen for molecules affecting p-body assembly. from a unique library of compounds derived from myxobacteria, 30 specifically inhibited p-body assembly. geph ... | 2013 | 24418890 |