Identification of the Cyclase Product and its First Oxidation Product in the Biosynthesis of Fuscol and Fuscosides

2010 ◽  
Vol 63 (6) ◽  
pp. 901 ◽  
Author(s):  
Maysoon B. Saleh ◽  
Russell G. Kerr
Keyword(s):  
Oxidation Product ◽  
Unsaturated Hydrocarbon ◽  
Cell Free Extract ◽  
Murine Models ◽  
Selective Action ◽  
Isolation And Characterization ◽  
A Cell ◽  
The Caribbean ◽  
Eunicea Fusca

Fuscol and the related fuscosides are diterpenes isolated from the Caribbean gorgonian Eunicea fusca, which exhibit potent anti-inflammatory activity with a selective action against leukotriene production in murine models. This report describes the isolation and characterization of the diterpene cyclase product leading to these natural products. The cyclase product has been assigned the trivial name eunicene A and was identified through a radioactivity-guided isolation. Additional biosynthetic experiments conducted by incubating a cell-free extract of E. fusca with 3H-labelled metabolites confirmed the involvement of this unsaturated hydrocarbon in the production of fuscol and fuscosides.

Isolation and characterization of a cell-associated protein of Bacillus pumilus PH-01

2001 ◽  
Vol 56 (3-4) ◽  
pp. 402-405 ◽  
Author(s):  
H.-B. Hong ◽  
Y.-S. Chang ◽  
S.-D. Choi ◽  
I.-H. Nam ◽  
Y.-E. Lee
Keyword(s):  
Bacillus Pumilus ◽  
Isolation And Characterization ◽  
A Cell

scholarly journals Characterization of a Novel Fructosyltransferase from Lactobacillus reuteri That Synthesizes High-Molecular-Weight Inulin and Inulin Oligosaccharides

2002 ◽  
Vol 68 (9) ◽  
pp. 4390-4398 ◽  
Author(s):  
S. A. F. T. van Hijum ◽  
G. H. van Geel-Schutten ◽  
H. Rahaoui ◽  
M. J. E. C. van der Maarel ◽  
L. Dijkhuizen
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Lactobacillus Reuteri ◽  
Bacterial Strains ◽  
Potential Health ◽  
Isolation And Characterization ◽  
A Cell ◽  
Encoding Gene ◽  
First Time

ABSTRACT Fructosyltransferase (FTF) enzymes produce fructose polymers (fructans) from sucrose. Here, we report the isolation and characterization of an FTF-encoding gene from Lactobacillus reuteri strain 121. A C-terminally truncated version of the ftf gene was successfully expressed in Escherichia coli. When incubated with sucrose, the purified recombinant FTF enzyme produced large amounts of fructo-oligosaccharides (FOS) with β-(2→1)-linked fructosyl units, plus a high-molecular-weight fructan polymer (>107) with β-(2→1) linkages (an inulin). FOS, but not inulin, was found in supernatants of L. reuteri strain 121 cultures grown on medium containing sucrose. Bacterial inulin production has been reported for only Streptococcus mutans strains. FOS production has been reported for a few bacterial strains. This paper reports the first-time isolation and molecular characterization of (i) a Lactobacillus ftf gene, (ii) an inulosucrase associated with a generally regarded as safe bacterium, (iii) an FTF enzyme synthesizing both a high molecular weight inulin and FOS, and (iv) an FTF protein containing a cell wall-anchoring LPXTG motif. The biological relevance and potential health benefits of an inulosucrase associated with an L. reuteri strain remain to be established.

scholarly journals Isolation and characterization of Chinese hamster ovary cell variants defective in adhesion to fibronectin-coated collagen.

1980 ◽  
Vol 87 (3) ◽  
pp. 755-763 ◽  
Author(s):  
P A Harper ◽  
R L Juliano
Keyword(s):  
Chinese Hamster Ovary ◽  
Cho Cells ◽  
Divalent Cations ◽  
Chinese Hamster ◽  
Ovary Cell ◽  
Human Diploid Fibroblasts ◽  
Isolation And Characterization ◽  
A Cell ◽  
Cold Insoluble Globulin

Variant clones of Chinese hamster ovary (CHO) cells were selected for reduced adhesion to serum-coated tissue culture plates. These clones also displayed reduced adhesion to substrata composed of collagen layers coated with bovine serum or with fibronectin (cold-insoluble globulin). Wild-type (WT) and adhesion variant (ADv) cells grew at comparable rates in suspension culture, but the adhesion variants could not be grown in monolayer culture because of their inability to attach to the substratum. The adhesion deficit in these cells was not corrected by raising the concentration of divalent cations or of serum to levels 10-fold greater than those normally utilized in cell culture. However, both WT and ADv clones could adhere, spread, and attain a normal CHO morphology on substrata coated with concanavalin A or poly-L-lysine. In addition, the adhesion variants could attach to substrata coated with "footpad" material (substratum-attached material) derived from monolayers of human diploid fibroblasts or WT CHO cells. These observations suggest that the variant clones may have a cell surface defect that prevents them from utilizing exogeneous fibronectin as an adhesion-promoting ligand; however the variants seem to have normal cytoskeletal and metabolic capacities that allow them to attach and spread on substrata coated with alternative ligands. These variants should be extremely useful in studying the molecular basis of cell adhesion.

scholarly journals Isolation and Characterization of a Genetically Tractable Photoautotrophic Fe(II)-Oxidizing Bacterium, Rhodopseudomonas palustris Strain TIE-1

2005 ◽  
Vol 71 (8) ◽  
pp. 4487-4496 ◽  
Author(s):  
Yongqin Jiao ◽  
Andreas Kappler ◽  
Laura R. Croal ◽  
Dianne K. Newman
Keyword(s):  
Bacterial Species ◽  
Rhodopseudomonas Palustris ◽  
Carbon Sources ◽  
Integral Membrane Protein ◽  
Transposition Frequency ◽  
Isolation And Characterization ◽  
Abc Transport ◽  
A Cell ◽  
Random Insertion

ABSTRACT We report the isolation and characterization of a phototrophic ferrous iron [Fe(II)]-oxidizing bacterium named TIE-1 that differs from other Fe(II)-oxidizing phototrophs in that it is genetically tractable. Under anaerobic conditions, TIE-1 grows photoautotrophically with Fe(II), H2, or thiosulfate as the electron donor and photoheterotrophically with a variety of organic carbon sources. TIE-1 also grows chemoheterotrophically in the dark. This isolate appears to be a new strain of the purple nonsulfur bacterial species Rhodopseudomonas palustris, based on physiological and phylogenetic analysis. Fe(II) oxidation is optimal at pH 6.5 to 6.9. The mineral products of Fe(II) oxidation are pH dependent: below pH 7.0 goethite (α-FeOOH) forms, and above pH 7.2 magnetite (Fe3O4) forms. TIE-1 forms colonies on agar plates and is sensitive to a variety of antibiotics. A hyperactive mariner transposon is capable of random insertion into the chromosome with a transposition frequency of ∼10−5. To identify components involved in phototrophic Fe(II) oxidation, mutants of TIE-1 were generated by transposon mutagenesis and screened for defects in Fe(II) oxidation in a cell suspension assay. Among approximately 12,000 mutants screened, 6 were identified that are specifically impaired in Fe(II) oxidation. Five of these mutants have independent disruptions in a gene that is predicted to encode an integral membrane protein that appears to be part of an ABC transport system; the sixth mutant has an insertion in a gene that is a homolog of CobS, an enzyme involved in cobalamin (vitamin B12) biosynthesis.

Disassembly of the Drosophila nuclear lamina in a homologous cell-free system

1995 ◽  
Vol 108 (5) ◽  
pp. 2027-2035 ◽  
Author(s):  
N. Maus ◽  
N. Stuurman ◽  
P.A. Fisher
Keyword(s):  
Nuclear Lamina ◽  
Meiotic Metaphase ◽  
Two Dimensional ◽  
Cell Free Extract ◽  
Free System ◽  
Nuclear Lamin ◽  
A Cell

Stage 14 Drosophila oocytes are arrested in first meiotic metaphase. A cell-free extract of these oocytes catalyzes apparent disassembly of purified Drosophila nuclei as well as of nuclear lamin polymers formed in vitro from isolated interphase lamins. Biochemically, the oocyte extract catalyzes lamin solubilization and phosphorylation as well as characteristic changes in one- and two-dimensional gel mobility. A previously unidentified soluble lamin isoform is easily seen after in vitro disassembly. This isoform is detectable but present only in very small quantities in vivo and is apparently derived specifically from one of the two interphase lamin isoforms. Cell-free nuclear lamina disassembly is ATP-dependent and addition of calcium to extracts blocks disassembly as judged both morphologically and biochemically. This system will allow enzymological characterization of cell-free lamina disassembly as well as molecular analysis of specific Drosophila mutants.

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