Search results for "Cysteine"
showing 10 items of 550 documents
Cerebral protection during fetal-to-neonatal transition under hypoxic atmosphere
2017
Newborn asphyxia is a complication during the perinatal period. The use of O2 for resuscitation has been broadly used in clinic. However, it has been demonstrated that oxygen overexposure induces oxidative stress (OS). We speculate that delaying postnatal in the extrauterine oxygenation status would preserve reducing equivalents, enhance redox adaptation, and protect oxyregulator tissues. The objective is evaluated OE status, induced by Fetal-Neonatal Transition (FNT) under different FiO2 conditions, in brain. FiO2 in pregnant mice was reduced from 21% to 14% or not the night before of delivery (G19). 8 hours after birth both group were led to room air (Hx14/21 and Nx21/21 groups) or hypero…
Cryptogein affects expression of alpha3, alpha6 and beta1 20S proteasome subunits encoding genes in tobacco.
2001
Twelve a and b 20S proteasome subunits cDNAs showing 70–82% identity with the corresponding genes in Arabidopsis or rice, and features of eukaryotic proteasome subunits were cloned in tobacco. Only b1-tcI 7, a3 and a6, 20S proteasome subunits encoding genes were up-regulated by cryptogein, a proteinaceous elicitor of plant defence reactions. These results led to the hypothesis that the activation of b1-tcI 7, a3 and a6 could induce a specific proteolysis involved in the hypersensitive response and systemic acquired resistance monitored by cryptogein. In eukaryotes, the 26S proteasome is the central multicatalytic proteinase complex comprising two subcomplexes: the 20S core particle that per…
Structure and function of the vacuolar Ccc1/VIT1 family of iron transporters and its regulation in fungi
2020
Iron is an essential micronutrient for most living beings since it participates as a redox active cofactor in many biological processes including cellular respiration, lipid biosynthesis, DNA replication and repair, and ribosome biogenesis and recycling. However, when present in excess, iron can participate in Fenton reactions and generate reactive oxygen species that damage cells at the level of proteins, lipids and nucleic acids. Organisms have developed different molecular strategies to protect themselves against the harmful effects of high concentrations of iron. In the case of fungi and plants, detoxification mainly occurs by importing cytosolic iron into the vacuole through the Ccc1/V…
Mutilation of RNA phage Qβ virus-like particles: from icosahedrons to rods
2000
Icosahedral virus-like particles (VLPs) of RNA phage Qbeta are stabilized by four disulfide bonds of cysteine residues 74 and 80 within the loop between beta-strands F and G (FG loop) of the monomeric subunits, which determine the five-fold and quasi-six-fold symmetry contacts of the VLPs. In order to reduce the stability of Qbeta VLPs, we mutationally converted the amino acid stretch 76-ANGSCD-81 within the FG loop into the 76-VGGVEL-81 sequence. It led to production in Escherichia coli cells of aberrant rod-like Qbeta VLPs, along with normal icosahedral capsids. The length of the rod-like particles exceeded 4-30 times the diameter of icosahedral Qbeta VLPs.
A20 deficiency in B cells enhances B-cell proliferation and results in the development of autoantibodies.
2011
A20/TNFAIP3 is an ubiquitin-editing enzyme, important for the regulation of the NF-κB pathway. Mutations in the TNFAIP3 gene have been linked to different human autoimmune disorders. In human B-cell lymphomas, the inactivation of A20 results in constitutive NF-κB activation. Recent studies demonstrate that in mice the germline inactivation of A20 leads to early lethality, due to inflammation in multiple organs of the body. In this report, we describe a new mouse strain allowing for the tissue-specific deletion of A20. We show that B-cell-specific deletion of A20 results in a dramatic reduction in marginal zone B cells. Furthermore, A20-deficient B cells display a hyperactive phenotype repre…
Disulfide stress and its targets in acute pancreatitis
2014
Under physiological conditions, the balance between ROS production and removal properly maintains the intracellular redox-sensitive signaling as well as the appropriate status of protein thiols and disulfides. However, inflammation among other factors can modify this balance causing a rapid increase in intracellular ROS levels and hence thiol oxidation, eventually leading to oxidative stress. In the case of acute pancreatitis, both redox signaling and oxidative stress seem to contribute to the progression of the severe form of the disease. In this review we will focus on the reversible oxidation of protein cysteines during the course of acute pancreatitis. We describe disulfide stress in an…
1,2,4-Oxadiazole topsentin analogs as staphylococcal biofilm inhibitors targeting the bacterial transpeptidase sortase A
2020
The inhibition or prevention of biofilm formation represents an emerging strategy in the war against antibiotic resistance, interfering with key players in bacterial virulence. This approach includes the inhibition of the catalytic activity of transpeptidase sortase A (Srt A), a membrane enzyme responsible for covalently attaching a wide variety of adhesive matrix molecules to the peptidoglycan cell wall in Gram-positive strains. A new series of seventeen 1,2,4-oxadiazole derivatives was efficiently synthesized and screened as potential new anti-virulence agents. The ability of inhibiting biofilm formation was evaluated against both Gram-positive and Gram-negative pathogens. Remarkably, all…
Association of redox and inflammation-related biomarkers with prognosis in IgA nephropathy: A prospective observational study.
2022
IgA nephropathy (IGAN) has a variable prognosis. Risk stratification tools are usually based on clinical parameters combined with histologic Oxford-MEST-C score. Circulating redox- and inflammation-related biomarkers may be related to histological changes in IGAN. Therefore, we studied the performance of these biomarkers in predicting the rate of GFR-loss in IGAN.This was an observational prospective study. Fifty-seven stable patients with IGAN were examined at baseline and after a mean observational time of 5.9 ± 1.1 years. The main outcome measure was eGFR-loss per year with predefined groups, stable (1.5 ml/min/1,73 mFifteen patients were in the progressive, 11 in the intermediate, and 3…
Development of novel dipeptide-like rhodesain inhibitors containing the 3-bromoisoxazoline warhead in a constrained conformation.
2015
Novel dipeptide-like rhodesain inhibitors containing the 3-bromoisoxazoline warhead in a constrained conformation were developed; some of them possess K(i) values in the micromolar range. We studied the structure-activity relationship of these derivatives and we performed docking studies, which allowed us to find out the key interactions established by the inhibitors with the target enzyme. Biological results indicate that the nature of the P2 and P3 substituents and their binding to the S2/S3 pockets is strictly interdependent.
Arsenic, antimony and bismuth complexation by L-cysteine in water
1984
Synthese, dans l'eau, des complexes L-cysteine: AsL 3 , SbL 3 •H 2 O et BiL 3 .H 2 O L=forme monoanionique de cysteine. Etude IR des structures