Search results for "T complex"
showing 10 items of 151 documents
Functionally active complement proteins C6 and C7 detected in C6- and C7-deficient individuals
1991
SUMMARYTwo sensitive sandwich ELISAs based on monoclonal antibodies directed to native C6 and C7 allowed the detection and quantitation of these complement proteins in 20 out of 37 serum samples from individuals who had previously been classified as deficient in these proteins as assessed by immunochemical and/or functional assays. Furthermore, serum from four C6-deficient and one combined C6-/C7-deficient individual showed an increase in the terminal complement complex (TCC) and a decrease in native C6 and C7 after complement activation as assayed by specific ELISAs. Despite their (incomplete) deficiencies, these individuals therefore possess functionally active terminal complement protein…
Tucupentol, a novel mono-tetrahydrofuranic acetogenin from Annona montana, as a potent inhibitor of mitochondrial complex I.
2009
Ten acetogenins, one of them new, were isolated from leaves and twigs of a Bolivian collection of Annona montana. The new compound that we named tucupentol (1) is a mono-tetrahydrofuranpentahydroxy-acetogenin. The inhibitory potency of tucupentol (1) on the mitochondrial complex I was evaluated, and this activity was compared with that of the known acetogenins, annonacin-A, cisannonacin-10-one, aromin, and gigantetronenin, also isolated from this plant material. The mentioned acetogenins acted as selective inhibitors of mitochondrial complex I in the 0.8-5.4-nM range. Fil: Álvarez Colom, Olga. Universidad Nacional de Tucumán. Facultad de Bioquímica, Química y Farmacia. Instituto de Química …
Effects of cadmium chloride on some mitochondria-related activity and gene expression of human MDA-MB231 breast tumor cells.
2007
It was reported that cadmium is able to exert a cytotoxic effect on tumor MDA-MB231 cells, which shows signs of "non-classical" apoptosis and is characterized by drastic changes in gene expression pattern. In this study, we have extended our knowledge of metal-breast cancer cell interactions by analyzing some mitochondria-related aspects of the stress response to CdCl(2) at either 5 or 50 microM 24- or 96-h exposure, by cytochemical, conventional PCR and Northern/Western blot techniques. We demonstrated that (i) no modification of the mitochondrial mass was detectable due to CdCl(2) exposure; (ii) the respiration activity appeared to be increased after 96-h exposures, while the production o…
X Chromosome Contribution to the Genetic Architecture of Primary Biliary Cholangitis
2021
Background & aims: Genome-wide association studies in primary biliary cholangitis (PBC) have failed to find X chromosome (chrX) variants associated with the disease. Here, we specifically explore the chrX contribution to PBC, a sexually dimorphic complex autoimmune disease. Methods: We performed a chrX-wide association study, including genotype data from 5 genome-wide association studies (from Italy, United Kingdom, Canada, China, and Japan; 5244 case patients and 11,875 control individuals). Results: Single-marker association analyses found approximately 100 loci displaying P < 5 × 10-4, with the most significant being a signal within the OTUD5 gene (rs3027490; P = 4.80 × 10-6; odds…
Menaquinone-dependent succinate dehydrogenase of bacteria catalyzes reversed electron transport driven by the proton potential.
1998
Succinate dehydrogenases from bacteria and archaea using menaquinone (MK) as an electron acceptor (succinate/menaquinone oxidoreductases) contain, or are predicted to contain, two heme-B groups in the membrane-anchoring protein(s), located close to opposite sides of the membrane. All succinate/ubiquinone oxidoreductases, however, contain only one heme-B molecule. In Bacillus subtilis and other bacteria that use MK as the respiratory quinone, the succinate oxidase activity (succinate-->O2), and the succinate/menaquinone oxidoreductase activity were specifically inhibited by uncoupler (CCCP, carbonyl cyanide m-chlorophenylhydrazone) or by agents dissipating the membrane potential (valinomycin…
Evidence for a selective and electroneutral K+/H+-exchange in Saccharomyces cerevisiae using plasma membrane vesicles
1996
The existence of a K+/H+ transport system in plasma membrane vesicles from Saccharomyces cerevisiae is demonstrated using fluorimetric monitoring of proton fluxes across vesicles (ACMA fluorescence quenching). Plasma membrane vesicles used for this study were obtained by a purification/reconstitution protocol based on differential and discontinuous sucrose gradient centrifugations followed by an octylglucoside dilution/gel filtration procedure. This method produces a high percentage of tightly-sealed inside-out plasma membrane vesicles. In these vesicles, the K+/H+ transport system, which is able to catalyse both K+ influx and efflux, is mainly driven by the K+ transmembrane gradient and ca…
Inclusion complexes of Cethyl-2-methylresorcinarene and pyridine N-oxides: breaking the C–I⋯−O–N+ halogen bond by host–guest complexation
2016
C ethyl-2-Methylresorcinarene forms host–guest complexes with aromatic N-oxides through multiple intra- and intermolecular hydrogen bonds and C–H⋯π interactions. The host shows conformational flexibility to accommodate 3-methylpyridine N-oxide, while retaining a crown conformation for 2-methyl- and 4-methoxypyridine N-oxides highlighting the substituent effect of the guest. N-Methylmorpholine N-oxide, a 6-membered ring aliphatic N-oxide with a methyl at the N-oxide nitrogen, is bound by the equatorial −N–CH3 group located deep in the cavity. 2-Iodopyridine N-oxide is the only guest that manifests intermolecular N–O⋯I–C halogen bond interactions, which are broken down by the host resulting i…
Halogen-bonded solvates of tetrahaloethynyl cavitands
2017
The formation and structures of halogen-bonded solvates of three different tetrahaloethynyl cavitands with acetone, chloroform, acetonitrile, DMF and DMSO were prepared and investigated. The inclusion and host–guest behaviour of the resorcinarene cavitands was found to be highly dependent on the flexibility of the ethylene-bridging unit.
Staining mitochondria in Saccharomyces cerevisiae.
1969
After testing various procedures (amidoblack 10B, acid fuchsin-methyl blue, Luxol fast blue MBS-phloxine, toluidine blue O, Jams green B and pinacyanol), three stains can be recommended for staining both types of mitochondria (globose and threadlike) in the cells of Saccharomyces cerevisiae: (1) 0.1% solution of amidoblack 10B in citrate buffer (pH 3.0) for 10 min; (2) 0.01% solution of toluidine blue O in phosphate buffer (pH 6.0) for 30 min; (3) 0.01% solution of Janus green B in distilled water (pH 5.6) for 30 min. The latter stain is most specific because its staining reaction depends upon the action of the mitochondrial enzyme cytochrome c oxidase. Yet, low concentrations and short inc…
Mitochondrial compartment: a possible target of cadmium effects on breast epithelial cells.
2009
Cadmium–breast epithelial cell interactions were studied by analyzing some mitochondria-related aspects of stress response. We treated immortalized non-tumor breast cells with 5 or 50 μM CdCl2 for 24 or 96 h demonstrating that the exposure did not cause a significant mitochondrial proliferation, while it induced a significant increase in the respiratory activity and mitochondrial polarization. In addition, we found that hsp60 was up-regulated while hsp70 and COXII and COXIV were down-regulated. The mRNA for hsp70 remained constant and only the inducible form of the 70-kDa heat shock protein was over expressed. The mRNAs for COXII and COXIV remained constant after 24 h and increased after lo…