Search results for "adenosine"

ETC-1002: A future option for lipid disorders?

2014

ETC-1002 is a new investigational low density lipoprotein cholesterol (LDL-C)-lowering agent (Esperion Therapeutics, Inc.). ETC-1002 is a dicarboxylic acid derivative with a novel mechanism of action targeting two hepatic enzymes - adenosine triphosphate-citrate lyase (ACL) and adenosine monophosphate-activated protein kinase (AMPK), inhibiting sterol and fatty acid synthesis and promoting mitochondrial long-chain fatty acid oxidation. This agent is currently in phase II clinical research. Available data report that ETC-1002 significantly decreased LDL-C levels (up to 32%) in both patients with normal and elevated baseline levels of triglycerides. Such beneficial effect is superior to curre…

Energetic coupling between plastids and mitochondria drives CO2 assimilation in diatoms.

2015

International audience; Diatoms are one of the most ecologically successful classes of photosynthetic marine eukaryotes in the contemporary oceans. Over the past 30 million years, they have helped to moderate Earth's climate by absorbing carbon dioxide from the atmosphere, sequestering it via the biological carbon pump and ultimately burying organic carbon in the lithosphere. The proportion of planetary primary production by diatoms in the modern oceans is roughly equivalent to that of terrestrial rainforests. In photosynthesis, the efficient conversion of carbon dioxide into organic matter requires a tight control of the ATP/NADPH ratio which, in other photosynthetic organisms, relies prin…

Thermodynamics and fluorescence emission studies on potential molecular chemosensors for ATP recognition in aqueous solution †

1999

The interaction of the open-chain polyamine N-(3-aminopropyl)-N′-[3-(anthrylmethyl)aminopropyl]ethane-1,2-diamine (L) with the relevant anionic forms of adenosine 5′-triphosphate (ATP), adenosine 5′-diphosphate (ADP) and adenosine 5′-monophosphate (AMP) is described. Unambiguous criteria for defining thermodynamic selectivity based on the use of effective stability constants are presented. The interaction of L and several other topologically similar polyammonium receptors with ATP has been shown to occur through electrostatic and π-stacking intermolecular forces. The π-stacking binding mode is modulated by the protonation degree of ATP as indicated by fluorescence emission titrations. Evide…

The rheumatoid arthritis shared epitope increases cellular susceptibility to oxidative stress by antagonizing an adenosine-mediated anti-oxidative pa…

2006

We have recently demonstrated that the rheumatoid arthritis (RA) shared epitope (SE) acts as a ligand that triggers nitric oxide (NO) signaling in opposite cells. Given the known pro-oxidative effect of NO and the proposed role of oxidative stress in the pathogenesis of RA, this study explores whether SE-triggered signaling can increase cellular oxidative stress. cAMP levels, adenylyl cyclase activity, and protein kinase A activity were measured using commercial kits. Generation of reactive oxygen species (ROS) was quantified using the fluorochrome dichlorofluorescein diacetate. Oxidative DNA damage was quantified using the single-cell electrophoresis technique. Here, we report that cells e…

Involvement of purinergic nerves in the NANC inhibitory junction potentials in pigeon oesophageal smooth muscle.

2004

1. Electrical field stimulation (EFS) (0.5 ms in train of 2-32 Hz for 300 ms) in smooth muscle of pigeon oesophagus, in the presence of atropine (1 microm) and guanethidine (1 microm), elicited an inhibitory response consisting of a transient hyperpolarization (inhibitory junction potential, IJP) associated with muscle relaxation. 2. Sodium nitroprusside (SNP, 100 microm) induced hyperpolarization correlated to mechanical relaxation. 3. The nitric oxide (NO) synthase inhibitor N(omega)-nitro-l-arginine (from 0.1 to 100 microm) caused a concentration-dependent reduction of electromechanical response to EFS indicating a role for NO in this response. 4. Apamin (1 microm) reduced both IJP and r…

Evidence that adenosine is not involved in the non-adrenergic non-cholinergic relaxation in the rat duodenum.

1990

In rat isolated duodenal segments, adenosine induced, in the presence of atropine and guanethidine, a dose-dependent, long-lasting (about 20 s), tetrodotoxin (TTX)-resistant relaxation both in endoluminal pressure and in isometric tension. Electrical field stimulation (EFS) induced, in the presence of atropine and guanethidine, a TTX-sensitive short-lasting (about 6 s) relaxation followed by a sustained rebound contraction. Theophylline, a P1 receptor antagonist, at the concentration of 100 microM caused a marked inhibition of the adenosine-induced relaxation, while the EFS-induced relaxation was not modified. Our results suggest that adenosine induces relaxation of the rat duodenal smooth …

The inhibition of Ca2+-ATPases of human erythrocyte membranes by covalent binding of ATP derivatives.

1982

UV-induced cross-linking of Tet repressor to DNA containing tet operator sequences and 8-azidoadenines.

1990

The synthesis of 8-azido-2'-deoxyadenosine-5'-triphosphate is described. The photoreactive dATP analog was characterized by thin layer chromatography, proton resonance spectroscopy, infrared spectroscopy and UV spectroscopy. Its photolysis upon UV irradiation was studied. After incorporation of this dATP analog into DNA containing the tet operator sequence the investigation of the interactions between tet operator DNA and Tet repressor protein by UV photocross-linking becomes possible. Photocross-linking of protein to DNA was demonstrated by the reduced migration of the DNA in SDS polyacrylamide gel electrophoresis. Addition of the inducer tetracycline prior to UV irradiation significantly …

The Low-Affinity ATP Binding Site of the Escherichia coli SecA Dimer Is Localized at the Subunit Interface

1997

The homodimeric SecA protein is the ATP-dependent force generator in the Escherichia coli precursor protein translocation cascade. SecA contains two essential nucleotide binding sites (NBSs), i.e., NBS1 and NBS2 that hind ATP with high and low affinity, respectively. The photoactivatable bifunctional cross-linking agent 3'-arylazido-8-azidoadenosine 5'-triphosphate (diN(3)ATP) was used to investigate the spatial arrangement of the nucleotide binding sites of SecA, DiN(3)ATP is an authentic ATP analogue as it supports SecA-dependent precursor protein translocation and translocation ATPase, UV-induced photo-cross-linking of the diN(3)ATP-bound SecA results in the formation of stable dimeric s…

Update on the detection of beta-exotoxin in Bacillus thuringiensis strains by HPLC analysis.

2001

Aims: The current work aimed to study the presence of β-exotoxin by high-performance liquid chromatography (HPLC) in supernatant fluids from final whole cultures of the 69 type strains and 13 subtypes of Bacillus thuringiensis strains, as well as from some insecticidal strains. Methods and Results: Results from HPLC and bioassays with Ephestia kuhniella (Lepidoptera Pyralidae) were compared. Type I β-exotoxin was only detected in type strains representing serotypes H1, H9 and H10a,10b. Discrepancies between HPLC and bioassays were found in H8a,8b and some insecticidal strains, which suggests the occurrence of another soluble toxin different from type I β-exotoxin, possibly type II β-exotoxi…