Search results for "RACE"
showing 10 items of 4458 documents
Separation of chitosomal chitin synthetase from cell-free extracts ofNeurospora crassa “Slime” variant agglutinated with concanavalin A
1989
Cell-free extracts of the wall-less slime variant ofNeurospora crassa were treated with concanavalin A (Con A); this treatment caused a massive agglutination of the particulate structures in the cell-free homogenate, although most (73%) of the chitin synthetase initially present in the cell-free extract remained in the supernatant obtained after sedimentation of the lectin-flocculated material. This chitin synthetase showed the sedimentation properties of chitosomes (unique microvesicular structures) and failed to bind [3H]Con A. A significant percentage (42%) of the chitin synthetase activity associated with the Con A-flocculated material probably corresponds to mechanically trapped chitos…
Molecular response to TBT stress in marine sponge Suberites domuncula: proteolytical cleavage and phosphorylation of KRS_SD protein kinase
2003
Abstract Marine sponges as sessile filter feeders are inevitably under a constant influence of changes in their environment. Mediation of extracellular signals and regulation of cellular response to environmental stress is a key function of cellular protein kinases. Expression, proteolytical cleavage and phosphorylation of stress-responsive KRS_SD protein kinase, in control and tributyl-tin (TBT) treated sponges were investigated. In control sponge, two KRS_SD proteins were expressed: KRS_SD1 (54 kDa) corresponding to KRS_SD calculated molecular weight, and KRS_SD2 (50 kDa). Exposure of sponges to TBT resulted in alteration of KRS_SD1 and KRS_SD2 expression levels and their phosphorylation …
Fragments of β-thymosin from the sea urchinParacentrotus lividusas potential antimicrobial peptides against staphylococcal biofilms
2012
The immune mediators in echinoderms can be a potential source of novel antimicrobial peptides (AMPs) applied toward controlling pathogenic staphylococcal biofilms that are intrinsically resistant to conventional antibiotics. The peptide fraction <5 kDa from the cytosol of coelomocytes of the sea urchin Paracentrotus lividus (5-CC) was tested against a group of Gram-positive and Gram-negative pathogen reference strains. The 5-CC of P. lividus was active against all planktonic-tested strains but also showed antibiofilm properties against staphylococcal strains. Additionally, we demonstrated the presence of three small peptides in the 5-CC belonging to segment 9-41 of a P. lividusβ-thymosin. T…
Role of the Well-Known Basic and Recently Discovered Acidic Glutathione S-Transferases in the Control of Genotoxic Metabolites
1991
Glutathione S-transferases (GSTs; E.C. 2. 5. 1. 18) are a family of enzymes which have increasingly attracted the interest of toxicologists, pharmacologists, biochemists and clinicians since their discovery in 1961 (1). Initially, GSTs were believed to serve as intracellular transport proteins for endogenous compounds with limited solubility in water, thus acting as an intracellular equivalent to albumin in blood plasma. In this assumed capacity of reversible binding and transport of various ligands, the corresponding protein was named ligandin (2). Following the discovery of abundant GST occurrence in most forms of aerobic life including plants, and the GST-catalysed conjugation of a wide …
(2aRS,3RS,4aSR,6aRS,6bSR)-3-Hydroxy-2a,3,4a,6,6a,6b-hexahydro-1,4-dioxacyclopenta[cd]pentalen-2(5H)-one
2007
The molecular structure of the title compound [enantiomers (VIII) and (VIIIa)], C8H10O4, was determined in the course of our studies on the synthesis of cyclopenta[1,2-b]furan-4-one derivatives. Tricyclic (VIIIa) consists of a planar bridged lactone unit and the two other ring systems in the envelope conformation. It contains five chiral C atoms and was obtained as a racemic mixture. The X-ray analysis showed the compound to possess a half-acetal unit with an endo orientation of the half-acetal ether bridge with respect to the lactone unit.
Properties of sea urchin coelomocyte agglutinins
1996
We examined some biological activities of a 200-kDa glycoprotein, referred to as Paracentrotus lividus vitellogenin, contained both in the coelomic fluid and in a subpopulation of coelomocytes called «colourless spherula cells». Cell-free coelomic fluid, coelomocyte lysate and supernatant obtained after coelomocyte washings were assayed for hemagglutinating activity. All samples agglutinated rabbit erythrocytes in a calcium-dependent way. The comparison between the electrophoretic patterns of erythrocyte lysates, before and after incubation with the coelomic fluid, revealed that a 200-kDa band was obtained from membranes of agglutinated erythrocytes. In addition, polyclonal antibodies again…
Oxygen Radical Scavengers
2010
The myocardium can tolerate only relatively short periods of total myocardial ischemia without myocardial cell death. Following short ischemic periods, ischemic damage is reversible by reperfusion. However, with increasing duration and severity of ischemia, the damage inflicted to cardiomyocytes following reperfusion becomes irreversible. The combined pathologic events in the myocardium that follow a critical period of ischemia and leading to either reversible or irreversible damage to both cardiomyocytes and cardiac microvasculature is known as ischemia-reperfusion injury (Goldhaber and Weiss 1992).
Cationic Au Nanoparticle Binding with Plasma Membrane-like Lipid Bilayers: Potential Mechanism for Spontaneous Permeation to Cells Revealed by Atomis…
2014
Despite being chemically inert as a bulk material, nanoscale gold can pose harmful side effects to living organisms. In particular, cationic Au nanoparticles (AuNP+) of 2 nm diameter or less permeate readily through plasma membranes and induce cell death. We report atomistic simulations of cationic Au nanoparticles interacting with realistic membranes and explicit solvent using a model system that comprises two cellular compartments, extracellular and cytosolic, divided by two asymmetric lipid bilayers. The membrane-AuNP+ binding and membrane reorganization processes are discovered to be governed by cooperative effects where AuNP+, counterions, water, and the two membrane leaflets all contr…
Versuche über die oxydation von polyacroleinen mit wasserstoffperoxyd und peressigsäure. Polymer acroleine. 8. Mitt.
1958
Polyacroleine werden durch verdunntes Wasserstoffperoxyd vollstandig abgebaut. Als Abbauprodukte konnten Kohlendioxyd, Ameisensaure und Essigsaure identifiziert werden. Daneben bilden sich noch unbekannte nicht-fluchtige Saren. Polyacrylsaure erleidet unter den gleichen Bedingungen ebenfalls einen Abbau. Die Zusammensetzung der Abbauprodukte ist eine andere. Durch Peressigsaure werden Polyacroleine zu polymeren Sauren oxydiert. Diese gleichen bezuglich der Loslichkeit, der Reaktionen mit Schwermetallsalzen und dem IR- Spektrum weitgehend der Polyacrylsaure. Polyacroleins are completely degraded by the action of dilute hydrogen peroxide. Among the products of degradation carbon dioxyde, form…
Luminescence properties of a cofacial dipalladium porphyrin dimer under argon and in the presence of dioxygen
2001
The preparation and luminescence properties of a dipalladium cofacial porphyrin dimer (DPA) Pd 2 (where DPA is the tetraanion of 1,8-bis(2,8,13,17-tetraethyl-3,7,12,18-tetramethylporphyrin-5-yl)anthracene) are reported and compared together with the photophysical behavior of the known monomeric (OEP)Pd and (TPP)Pd complexes. The effect of dioxygen in the presence and in the absence of the very bulky base, 1-t-butyl-5-phenylimidazole, is also investigated. The title dimer, (DPA) Pd 2, shows fluorescence and phosphorescence in the ps and ms time scale, respectively, with a global intensity lower than that of the porphyrin monomer analogues. The fluorescence sensitivity towards dioxygen quenc…