Search results for "hate"
showing 10 items of 2099 documents
Phosphate-controlled regulator for the biosynthesis of the dalbavancin precursor A40926
2007
ABSTRACT The actinomycete Nonomuraea sp. strain ATCC 39727 produces the glycopeptide A40926, the precursor of the novel antibiotic dalbavancin. Previous studies have shown that phosphate limitation results in enhanced A40926 production. The A40926 biosynthetic gene ( dbv ) cluster, which consists of 37 genes, encodes two putative regulators, Dbv3 and Dbv4, as well as the response regulator (Dbv6) and the sensor-kinase (Dbv22) of a putative two-component system. Reverse transcription-PCR (RT-PCR) and real-time RT-PCR analysis revealed that the dbv14 - dbv8 and the dbv30 - dbv35 operons, as well as dbv4 , were negatively influenced by phosphate. Dbv4 shows a putative helix-turn-helix DNA-bind…
Glutathione metabolism under the influence of hydroperoxides in the lactating mammary gland of the rat. Effect of glucose and extracellular ATP.
1987
Tert-butyl hydroperoxide decreases GSH and total free glutathione (GSH+2GSSG) contents of acini from lactating mammary glands. The decrease in total free glutathione can be explained by an increase in mixed disulfide formation and by excretion of GSS G to the extracellular medium, and subsequent degradation catalyzed by gamma-glutamyl transpeptidase. Low concentrations of glucose prevented the changes in glutathione levels induced by the peroxide. In the presence of extracellular ATP, glucose did not prevent these changes. However, incubations with the peroxide, did not alter the rate of other metabolic pathways by acini.
Binding and/or hydrolysis of purine‐based nucleotides is not required for IM30 ring formation
2021
IM30, the inner membrane-associated protein of 30 kDa, is conserved in cyanobacteria and chloroplasts. Although its exact physiological function is still mysterious, IM30 is clearly essential for thylakoid membrane biogenesis and/or dynamics. Recently, a cryptic IM30 GTPase activity has been reported, albeit thus far no physiological function has been attributed to this. Yet, it is still possible that GTP binding/hydrolysis affects formation of the prototypical large homo-oligomeric IM30 ring and rod structures. Here, we show that the Synechocystis sp. PCC 6803 IM30 protein in fact is an NTPase that hydrolyzes GTP and ATP, but not CTP or UTP, with about identical rates. While IM30 forms lar…
Molecular recognition of nucleotides in water by scorpiand-type receptors based on nucleobase discrimination.
2014
Abstract: The detection of nucleotides is of crucial impor-tance because they are the basic building blocks of nucleicacids. Scorpiand-based polyamine receptors functionalizedwith pyridine or anthracene units are able to form stablecomplexes with nucleotides in water, based on coulombic,p–p stacking, and hydrogen-bonding interactions. This be-havior has been rationalized by means of an explorationwith NMR spectroscopy and DFT calculations. Binding con-stants were determined by potentiometry. Fluorescencespectroscopy studies have revealed the potential of these re-ceptors as sensors to effectively and selectively distinguishguanosine-5’-triphosphate (GTP) from adenosine-5’-triphos-phate (ATP…
Selective Stimulation of Hepatitis C Virus and Pestivirus NS5B RNA Polymerase Activity by GTP
1999
NS5B of the hepatitis C virus is an RNA template-dependent RNA polymerase and therefore the key player of the viral replicase complex. Using a highly purified enzyme expressed with recombinant baculoviruses in insect cells, we demonstrate a stimulation of RNA synthesis up to 2 orders of magnitude by high concentrations of GTP but not with ATP, CTP, UTP, GDP, or GMP. Enhancement of RNA synthesis was found with various heteropolymeric RNA templates, with poly(C)-oligo(G)12 but not with poly(A)-oligo(U)12. Several amino acid substitutions in polymerase motifs B, C, and D previously shown to be crucial for RdRp activity were tested for GTP stimulation of RNA synthesis. Most of these mutations, …
RAB3GAP1 and RAB3GAP2 modulate basal and rapamycin-induced autophagy
2014
Macroautophagy is a degradative pathway that sequesters and transports cytosolic cargo in autophagosomes to lysosomes, and its deterioration affects intracellular proteostasis. Membrane dynamics accompanying autophagy are mostly elusive and depend on trafficking processes. RAB GTPase activating proteins (RABGAPs) are important factors for the coordination of cellular vesicle transport systems, and several TBC (TRE2-BUB2-CDC16) domain-containing RABGAPs are associated with autophagy. Employing C. elegans and human primary fibroblasts, we show that RAB3GAP1 and RAB3GAP2, which are components of the TBC domain-free RAB3GAP complex, influence protein aggregation and affect autophagy at basal an…
Structural features of the human bradykinin B2 receptor probed by agonists, antagonists, and anti-idiotypic antibodies
1993
The human bradykinin B2 receptor belongs to the family of G-protein-coupled receptors. To characterize the receptor protein, we have solubilized the membranes of cultured human foreskin fibroblasts bearing the B2 receptor. Affinity cross-linking of the solubilized receptor with the labeled agonist, 125I-Tyr0-bradykinin, or the labeled antagonist, 125I-(4-hydroxy-phenyl-propionyl)-HOE140, revealed major bands of apparent molecular mass of 69 kDa in SDS-polyacrylamide gel electrophoresis under reducing conditions, and of 59 kDa under non-reducing conditions. A 1000-fold molar excess of each of the unlabeled ligands quenched the specific labeling suggesting that the agonist and the antagonist …
Nitric Oxide/Cyclic Guanosine Monophosphate Signaling via Guanylyl Cyclase Isoform 1 Mediates Early Changes in Synaptic Transmission and Brain Edema …
2021
Traumatic brain injury (TBI) often induces structural damage, disruption of the blood-brain barrier (BBB), neurodegeneration, and dysfunctions of surviving neuronal networks. Nitric oxide (NO) signaling has been suggested to affect brain functions after TBI. The NO exhibits most of its biological effects by activation of the primary targets-guanylyl cyclases (NO-GCs), which exists in two isoforms (NO-GC1 and NO-GC2), and the subsequently produced cyclic guanosine monophosphate (cGMP). However, the specific function of the NO-NO-GCs-cGMP pathway in the context of brain injury is not fully understood. To investigate the specific role of the isoform NO-GC1 early after brain injuries, we perfor…
Use of Calcined Dolomite as Chemical Precipitant in the Simultaneous Removal of Ammonium and Phosphate from Synthetic Wastewater and from Agricultura…
2019
Phosphorus as phosphate and nitrogen as ammonium or nitrate are the main nutrients in wastewaters and agricultural sludges. They runoff easily to waterways and cause eutrophication in water bodies. However, ammonium and phosphate could be precipitated simultaneously and used as recycled nutrients. In this research, dolomite calcined at 650 °
A bio-imitating approach to fabricate an artificial matrix for cartilage tissue engineering using magnesium-polyphosphate and hyaluronic acid
2016
Here we describe an artificial cartilage-like material based on a hyaluronic acid-Mg/Ca-polyphosphate paste (HA-aMg/Ca-polyP-p) that is fabricated from a water-soluble Na-salt of energy-rich inorganic polyphosphate (polyP) and soluble hyaluronic acid in the presence of water-insoluble CaCO3. The resulting material, after conversion of Na-polyP into the less soluble Mg/Ca-salt consisting of amorphous Mg/Ca-polyP microparticles, was found to mimic the physiological cartilage tissue and to bind Ca2+ ions present in the synovial fluid. After the Mg2+/Ca2+ exchange and water extrusion, the polyP becomes more stable, but is still susceptible to hydrolytic cleavage by the alkaline phosphatase (ALP…