Search results for "serp"
showing 10 items of 205 documents
Functional and dysfunctional conformers of human neuroserpin characterized by optical spectroscopies and Molecular Dynamics
2015
Neuroserpin (NS) is a serine protease inhibitor (SERPIN) involved in different neurological pathologies, including the Familial Encephalopathy with Neuroserpin Inclusion Bodies (FENIB), related to the aberrant polymerization of NS mutants. Here we present an in vitro and in silico characterization of native neuroserpin and its dysfunctional conformation isoforms: the proteolytically cleaved conformer, the inactive latent conformer, and the polymeric species. Based on circular dichroism and fluorescence spectroscopy, we present an experimental validation of the latent model and highlight the main structural features of the different conformers. In particular, emission spectra of aromatic res…
Production of reactive oxygen intermediates by human macrophages exposed to soot particles and asbestos fibers and increase in NF-kappa B p50/p105 mR…
1999
Alveolar macrophages (AM) play a decisive role in the immunologic defense system of the lung and in inflammatory pulmonary pathomechanisms. AM and blood monocytes (BM) were exposed to chrysotile B, soot FR 101, and Printex 90 (P 90). We evaluated the reactive oxygen intermediate (ROI) release of AM and BM after particle exposure. ROI release was measured by chemiluminescence. Thirty-minute exposure caused a significant (up to 2.5-fold) increase in ROI release of AM (100 micrograms/10(6) cells) compared with control experiments (p0.01). Identical exposure conditions for BM resulted in a similar reaction pattern (maximum 2.2-fold increase in ROI release; p0.05). After a 90-min particle exposu…
Molecular cloning and functional bacterial expression of a plant glucosidase specifically involved in alkaloid biosynthesis.
2000
Monoterpenoid indole alkaloids are a vast and structurally complex group of plant secondary compounds. In contrast to other groups of plant products which produce many glycosides, indole alkaloids rarely occur as glucosides. Plants of Rauvolfia serpentina accumulate ajmaline as a major alkaloid, whereas cell suspension cultures of Rauvolfia mainly accumulate the glucoalkaloid raucaffricine at levels of 1.6 g/l. Cell cultures do contain a specific glucosidase. known as raucaffricine-O-beta-D-glucosidase (RG), which catalyzes the in vitro formation of vomilenine, a direct intermediate in ajmaline biosynthesis. Here, we describe the molecular cloning and functional expression of this enzyme in…
Vinorine synthase from Rauvolfia: the first example of crystallization and preliminary X-ray diffraction analysis of an enzyme of the BAHD superfamily
2004
Abstract Crystals of vinorine synthase (VS) from medicinal plant Rauvolfia serpentina expressed in Escherichia coli have been obtained by the hanging-drop technique at 305 K with ammonium sulfate and PEG 400 as precipitants. The enzyme is involved in the biosynthesis of the antiarrhythmic drug ajmaline and is a member of the BAHD superfamily of acyltransferases. So far, no three-dimensional structure of a member of this enzyme family is known. The crystals belong to the space group P 2 1 2 1 2 1 with cell dimensions of a =82.3 A, b =89.6 A and c =136.2 A. Under cryoconditions (120 K), a complete data set up to 2.8 A was collected at a synchrotron source.
Heterologous expression, purification, crystallization and preliminary X-ray analysis of raucaffricine glucosidase, a plant enzyme specifically invol…
2006
Raucaffricine glucosidase (RG) is an enzyme that is specifically involved in the biosynthesis of indole alkaloids from the plant Rauvolfia serpentina. After heterologous expression in Escherichia coli cells, crystals of RG were obtained by the hanging-drop vapour-diffusion technique at 293 K with 0.3 M ammonium sulfate, 0.1 M sodium acetate pH 4.6 buffer and 11% PEG 4000 as precipitant. Crystals belong to space group I222 and diffract to 2.30 A, with unit-cell parameters a = 102.8, b = 127.3, c = 215.8 A.
Hydroquinone: O-glucosyltransferase from cultivated Rauvolfia cells: enrichment and partial amino acid sequences.
2000
Plant cell suspension cultures of Rauvolfia are able to produce a high amount of arbutin by glucosylation of exogenously added hydroquinone. A four step purification procedure using anion exchange, hydrophobic interaction, hydroxyapatite-chromatography and chromatofocusing delivered in a yield of 0.5%, an approximately 390 fold enrichment of the involved glucosyltransferase. SDS-PAGE showed a M(r) for the enzyme of 52 kDa. Proteolysis of the pure enzyme with endoproteinase LysC revealed six peptide fragments with 9-23 amino acids which were sequenced. Sequence alignment of the six peptides showed high homologies to glycosyltransferases from other higher plants.
Crystallization and preliminary X-ray crystallographic analysis of strictosidine synthase from Rauvolfia: the first member of a novel enzyme family.
2004
Strictosidine synthase is a central enzyme involved in the biosynthesis of almost all plant monoterpenoid indole alkaloids. Strictosidine synthase from Rauvolfia serpentina was heterologously expressed in Escherichia coli. Crystals of the purified recombinant enzyme have been obtained by the hanging-drop technique at 303 K with potassium sodium tartrate tetrahydrate as precipitant. The crystals belong to the space group R3 with cell dimensions of a=b=150.3 A and c=122.4 A. Under cryoconditions (120 K), the crystals diffract to about 2.95 A.
Distribución, abundancia y papel epidemiológico de los Simuliidae del río Serpis
2014
Los Simuliidae (Diptera, Nematocera) constituyen uno de los grupos de insectos de gran notoriedad en Salud Pública no sólo por su molesta mordedura sino, sobre todo, por los efectos que este acto puede originar y que van desde las simples reacciones alérgicas a dermatitis severas y enfermedades graves, como la oncocercosis, que anualmente afecta a millares de seres humanos. Este hecho hace necesario abordar planes de control contra las especies nocivas del grupo y para ello es necesario un conocimiento previo y preciso de la distribución de las especies, su biología y etología. Solo de este modo se pueden abordar planes de acción dirigidos específicamente al control de las poblaciones trans…
Synergy and Antagonism of Active Constituents of ADAPT-232 on Transcriptional Level of Metabolic Regulation of Isolated Neuroglial Cells
2013
Gene expression profiling was performed on the human neuroglial cell line T98G after treatment with adaptogen ADAPT-232 and its constituents - extracts of Eleutherococcus senticosus root, Schisandra chinensis berry, and Rhodiola rosea root as well as several constituents individually, namely, eleutheroside E, schizandrin B, salidroside, triandrin, and tyrosol. A common feature for all tested adaptogens was their effect on G-protein-coupled receptor signaling pathways, i.e., cAMP, phospholipase C (PLC), and phosphatidylinositol signal transduction pathways. Adaptogens may reduce the cAMP level in brain cells by down-regulation of adenylate cyclase gene ADC2Y and up-regulation of phosphodiest…
Purification and partial amino acid sequences of the enzyme vinorine synthase involved in a crucial step of ajmaline biosynthesis.
2004
The acetyl-CoA-dependent enzyme vinorine synthase was isolated from hybrid cell suspension cultures of Rauvolfia serpentina and Rhazya stricta. The sarpagan-type alkaloid gardneral was used as a substrate of the enzyme leading to the ajmalan-type 10-methoxyvinorine. An HPLC-based assay was developed to monitor vinorine synthase activity, which allowed establishing a five step purification procedure combining anion exchange, hydrophobic interaction, hydroxyapatite and gel filtration. Purification resulted in a yield of 0.2% and an approximately 991-fold enrichment of the acetyltransfer activity. SDS-PAGE analysis showed a Mr for the enzyme of approximately 50 kDa. The four peptide fragments …