Dithiothreitol: A reagent commonly used in biochemical studies as a protective agent to prevent the oxidation of SH (thiol) groups and for reducing disulphides to dithiols.Reducing Agents: Materials that add an electron to an element or compound, that is, decrease the positiveness of its valence. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 5th ed)Sulfhydryl Reagents: Chemical agents that react with SH groups. This is a chemically diverse group that is used for a variety of purposes. Among these are enzyme inhibition, enzyme reactivation or protection, and labelling.Sulfhydryl Compounds: Compounds containing the -SH radical.Disulfides: Chemical groups containing the covalent disulfide bonds -S-S-. The sulfur atoms can be bound to inorganic or organic moieties.Oxidation-Reduction: A chemical reaction in which an electron is transferred from one molecule to another. The electron-donating molecule is the reducing agent or reductant; the electron-accepting molecule is the oxidizing agent or oxidant. Reducing and oxidizing agents function as conjugate reductant-oxidant pairs or redox pairs (Lehninger, Principles of Biochemistry, 1982, p471).MercaptoethanolCysteine: A thiol-containing non-essential amino acid that is oxidized to form CYSTINE.Ethylmaleimide: A sulfhydryl reagent that is widely used in experimental biochemical studies.Kinetics: The rate dynamics in chemical or physical systems.Dithionitrobenzoic Acid: A standard reagent for the determination of reactive sulfhydryl groups by absorbance measurements. It is used primarily for the determination of sulfhydryl and disulfide groups in proteins. The color produced is due to the formation of a thio anion, 3-carboxyl-4-nitrothiophenolate.Diamide: A sulfhydryl reagent which oxidizes sulfhydryl groups to the disulfide form. It is a radiation-sensitizing agent of anoxic bacterial and mammalian cells.Glutathione: A tripeptide with many roles in cells. It conjugates to drugs to make them more soluble for excretion, is a cofactor for some enzymes, is involved in protein disulfide bond rearrangement and reduces peroxides.Iodobenzoates: Benzoic acid esters or salts substituted with one or more iodine atoms.Enzyme Reactivators: Compounds which restore enzymatic activity by removing an inhibitory group bound to the reactive site of the enzyme.Molecular Weight: The sum of the weight of all the atoms in a molecule.Hydrogen-Ion Concentration: The normality of a solution with respect to HYDROGEN ions; H+. It is related to acidity measurements in most cases by pH = log 1/2[1/(H+)], where (H+) is the hydrogen ion concentration in gram equivalents per liter of solution. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)Electrophoresis, Polyacrylamide Gel: Electrophoresis in which a polyacrylamide gel is used as the diffusion medium.Iodoacetamide: An alkylating sulfhydryl reagent. Its actions are similar to those of iodoacetate.Thioredoxins: Hydrogen-donating proteins that participates in a variety of biochemical reactions including ribonucleotide reduction and reduction of PEROXIREDOXINS. Thioredoxin is oxidized from a dithiol to a disulfide when acting as a reducing cofactor. The disulfide form is then reduced by NADPH in a reaction catalyzed by THIOREDOXIN REDUCTASE.Chloromercuribenzoates: Chloride and mercury-containing derivatives of benzoic acid.Hydroxymercuribenzoates: Hydroxylated benzoic acid derivatives that contain mercury. Some of these are used as sulfhydryl reagents in biochemical studies.Thimerosal: An ethylmercury-sulfidobenzoate that has been used as a preservative in VACCINES; ANTIVENINS; and OINTMENTS. It was formerly used as a topical antiseptic. It degrades to ethylmercury and thiosalicylate.Dithioerythritol: A compound that, along with its isomer, Cleland's reagent (DITHIOTHREITOL), is used for the protection of sulfhydryl groups against oxidation to disulfides and for the reduction of disulfides to sulfhydryl groups.Edetic Acid: A chelating agent that sequesters a variety of polyvalent cations such as CALCIUM. It is used in pharmaceutical manufacturing and as a food additive.Glutathione Disulfide: A GLUTATHIONE dimer formed by a disulfide bond between the cysteine sulfhydryl side chains during the course of being oxidized.Chromatography, Gel: Chromatography on non-ionic gels without regard to the mechanism of solute discrimination.Substrate Specificity: A characteristic feature of enzyme activity in relation to the kind of substrate on which the enzyme or catalytic molecule reacts.Hydrogen Peroxide: A strong oxidizing agent used in aqueous solution as a ripening agent, bleach, and topical anti-infective. It is relatively unstable and solutions deteriorate over time unless stabilized by the addition of acetanilide or similar organic materials.Amino Acid Sequence: The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.Molecular Sequence Data: Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.Enzyme Activation: Conversion of an inactive form of an enzyme to one possessing metabolic activity. It includes 1, activation by ions (activators); 2, activation by cofactors (coenzymes); and 3, conversion of an enzyme precursor (proenzyme or zymogen) to an active enzyme.Cattle: Domesticated bovine animals of the genus Bos, usually kept on a farm or ranch and used for the production of meat or dairy products or for heavy labor.Macromolecular Substances: Compounds and molecular complexes that consist of very large numbers of atoms and are generally over 500 kDa in size. In biological systems macromolecular substances usually can be visualized using ELECTRON MICROSCOPY and are distinguished from ORGANELLES by the lack of a membrane structure.Dimercaprol: An anti-gas warfare agent that is effective against Lewisite (dichloro(2-chlorovinyl)arsine) and formerly known as British Anti-Lewisite or BAL. It acts as a chelating agent and is used in the treatment of arsenic, gold, and other heavy metal poisoning.Escherichia coli: A species of gram-negative, facultatively anaerobic, rod-shaped bacteria (GRAM-NEGATIVE FACULTATIVELY ANAEROBIC RODS) commonly found in the lower part of the intestine of warm-blooded animals. It is usually nonpathogenic, but some strains are known to produce DIARRHEA and pyogenic infections. Pathogenic strains (virotypes) are classified by their specific pathogenic mechanisms such as toxins (ENTEROTOXIGENIC ESCHERICHIA COLI), etc.p-Chloromercuribenzoic Acid: An organic mercurial used as a sulfhydryl reagent.S-Nitrosoglutathione: A sulfur-containing alkyl thionitrite that is one of the NITRIC OXIDE DONORS.Oxidants: Electron-accepting molecules in chemical reactions in which electrons are transferred from one molecule to another (OXIDATION-REDUCTION).Cystamine: A radiation-protective agent that interferes with sulfhydryl enzymes. It may also protect against carbon tetrachloride liver damage.Iodoacetates: Iodinated derivatives of acetic acid. Iodoacetates are commonly used as alkylating sulfhydryl reagents and enzyme inhibitors in biochemical research.Protein Conformation: The characteristic 3-dimensional shape of a protein, including the secondary, supersecondary (motifs), tertiary (domains) and quaternary structure of the peptide chain. PROTEIN STRUCTURE, QUATERNARY describes the conformation assumed by multimeric proteins (aggregates of more than one polypeptide chain).Phosphorous Acids: Inorganic derivatives of phosphorus trihydroxide (P(OH)3) and its tautomeric form dihydroxyphosphine oxide (HP=O(OH)2). Note that organic derivatives of phosphonic acids are listed under are ORGANOPHOSPHONATES.Temperature: The property of objects that determines the direction of heat flow when they are placed in direct thermal contact. The temperature is the energy of microscopic motions (vibrational and translational) of the particles of atoms.Amino Acids: Organic compounds that generally contain an amino (-NH2) and a carboxyl (-COOH) group. Twenty alpha-amino acids are the subunits which are polymerized to form proteins.Adenosine Triphosphate: An adenine nucleotide containing three phosphate groups esterified to the sugar moiety. In addition to its crucial roles in metabolism adenosine triphosphate is a neurotransmitter.Hot Temperature: Presence of warmth or heat or a temperature notably higher than an accustomed norm.Binding Sites: The parts of a macromolecule that directly participate in its specific combination with another molecule.Chromatography, Ion Exchange: Separation technique in which the stationary phase consists of ion exchange resins. The resins contain loosely held small ions that easily exchange places with other small ions of like charge present in solutions washed over the resins.Trypsin: A serine endopeptidase that is formed from TRYPSINOGEN in the pancreas. It is converted into its active form by ENTEROPEPTIDASE in the small intestine. It catalyzes hydrolysis of the carboxyl group of either arginine or lysine. EC 3.4.21.4.Rabbits: The species Oryctolagus cuniculus, in the family Leporidae, order LAGOMORPHA. Rabbits are born in burrows, furless, and with eyes and ears closed. In contrast with HARES, rabbits have 22 chromosome pairs.Cystine: A covalently linked dimeric nonessential amino acid formed by the oxidation of CYSTEINE. Two molecules of cysteine are joined together by a disulfide bridge to form cystine.NADP: Nicotinamide adenine dinucleotide phosphate. A coenzyme composed of ribosylnicotinamide 5'-phosphate (NMN) coupled by pyrophosphate linkage to the 5'-phosphate adenosine 2',5'-bisphosphate. It serves as an electron carrier in a number of reactions, being alternately oxidized (NADP+) and reduced (NADPH). (Dorland, 27th ed)Chromatography, High Pressure Liquid: Liquid chromatographic techniques which feature high inlet pressures, high sensitivity, and high speed.Cations, Divalent: Positively charged atoms, radicals or groups of atoms with a valence of plus 2, which travel to the cathode or negative pole during electrolysis.Nitroso CompoundsChromatography, Affinity: A chromatographic technique that utilizes the ability of biological molecules to bind to certain ligands specifically and reversibly. It is used in protein biochemistry. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)Magnesium: A metallic element that has the atomic symbol Mg, atomic number 12, and atomic weight 24.31. It is important for the activity of many enzymes, especially those involved in OXIDATIVE PHOSPHORYLATION.Calcium: A basic element found in nearly all organized tissues. It is a member of the alkaline earth family of metals with the atomic symbol Ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth. It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in many enzymatic processes.Liver: A large lobed glandular organ in the abdomen of vertebrates that is responsible for detoxification, metabolism, synthesis and storage of various substances.Chloroplast Thioredoxins: A subtype of thioredoxins found primarily in CHLOROPLASTS.Affinity Labels: Analogs of those substrates or compounds which bind naturally at the active sites of proteins, enzymes, antibodies, steroids, or physiological receptors. These analogs form a stable covalent bond at the binding site, thereby acting as inhibitors of the proteins or steroids.Alkylation: The covalent bonding of an alkyl group to an organic compound. It can occur by a simple addition reaction or by substitution of another functional group.Cross-Linking Reagents: Reagents with two reactive groups, usually at opposite ends of the molecule, that are capable of reacting with and thereby forming bridges between side chains of amino acids in proteins; the locations of naturally reactive areas within proteins can thereby be identified; may also be used for other macromolecules, like glycoproteins, nucleic acids, or other.Isomerases: A class of enzymes that catalyze geometric or structural changes within a molecule to form a single product. The reactions do not involve a net change in the concentrations of compounds other than the substrate and the product.(from Dorland, 28th ed) EC 5.Chemistry: A basic science concerned with the composition, structure, and properties of matter; and the reactions that occur between substances and the associated energy exchange.Peroxides: A group of compounds that contain a bivalent O-O group, i.e., the oxygen atoms are univalent. They can either be inorganic or organic in nature. Such compounds release atomic (nascent) oxygen readily. Thus they are strong oxidizing agents and fire hazards when in contact with combustible materials, especially under high-temperature conditions. The chief industrial uses of peroxides are as oxidizing agents, bleaching agents, and initiators of polymerization. (From Hawley's Condensed Chemical Dictionary, 11th ed)Cytosol: Intracellular fluid from the cytoplasm after removal of ORGANELLES and other insoluble cytoplasmic components.Protein Folding: Processes involved in the formation of TERTIARY PROTEIN STRUCTURE.Enzyme Stability: The extent to which an enzyme retains its structural conformation or its activity when subjected to storage, isolation, and purification or various other physical or chemical manipulations, including proteolytic enzymes and heat.Chemical Phenomena: The composition, conformation, and properties of atoms and molecules, and their reaction and interaction processes.Protein Disulfide-Isomerases: Sulfur-sulfur bond isomerases that catalyze the rearrangement of disulfide bonds within proteins during folding. Specific protein disulfide-isomerase isoenzymes also occur as subunits of PROCOLLAGEN-PROLINE DIOXYGENASE.Cell Membrane: The lipid- and protein-containing, selectively permeable membrane that surrounds the cytoplasm in prokaryotic and eukaryotic cells.Oxidoreductases: The class of all enzymes catalyzing oxidoreduction reactions. The substrate that is oxidized is regarded as a hydrogen donor. The systematic name is based on donor:acceptor oxidoreductase. The recommended name will be dehydrogenase, wherever this is possible; as an alternative, reductase can be used. Oxidase is only used in cases where O2 is the acceptor. (Enzyme Nomenclature, 1992, p9)Recombinant Proteins: Proteins prepared by recombinant DNA technology.Mersalyl: A toxic thiol mercury salt formerly used as a diuretic. It inhibits various biochemical functions, especially in mitochondria, and is used to study those functions.Detergents: Purifying or cleansing agents, usually salts of long-chain aliphatic bases or acids, that exert cleansing (oil-dissolving) and antimicrobial effects through a surface action that depends on possessing both hydrophilic and hydrophobic properties.Protein Binding: The process in which substances, either endogenous or exogenous, bind to proteins, peptides, enzymes, protein precursors, or allied compounds. Specific protein-binding measures are often used as assays in diagnostic assessments.Isoelectric Focusing: Electrophoresis in which a pH gradient is established in a gel medium and proteins migrate until they reach the site (or focus) at which the pH is equal to their isoelectric point.Rats, Inbred Strains: Genetically identical individuals developed from brother and sister matings which have been carried out for twenty or more generations or by parent x offspring matings carried out with certain restrictions. This also includes animals with a long history of closed colony breeding.NAD: A coenzyme composed of ribosylnicotinamide 5'-diphosphate coupled to adenosine 5'-phosphate by pyrophosphate linkage. It is found widely in nature and is involved in numerous enzymatic reactions in which it serves as an electron carrier by being alternately oxidized (NAD+) and reduced (NADH). (Dorland, 27th ed)Protein Denaturation: Disruption of the non-covalent bonds and/or disulfide bonds responsible for maintaining the three-dimensional shape and activity of the native protein.Nitric Oxide Donors: A diverse group of agents, with unique chemical structures and biochemical requirements, which generate NITRIC OXIDE. These compounds have been used in the treatment of cardiovascular diseases and the management of acute myocardial infarction, acute and chronic congestive heart failure, and surgical control of blood pressure. (Adv Pharmacol 1995;34:361-81)Solubility: The ability of a substance to be dissolved, i.e. to form a solution with another substance. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)PeroxidasesChromatography: Techniques used to separate mixtures of substances based on differences in the relative affinities of the substances for mobile and stationary phases. A mobile phase (fluid or gas) passes through a column containing a stationary phase of porous solid or liquid coated on a solid support. Usage is both analytical for small amounts and preparative for bulk amounts.Sperm Head: The anterior portion of the spermatozoon (SPERMATOZOA) that contains mainly the nucleus with highly compact CHROMATIN material.Plants: Multicellular, eukaryotic life forms of kingdom Plantae (sensu lato), comprising the VIRIDIPLANTAE; RHODOPHYTA; and GLAUCOPHYTA; all of which acquired chloroplasts by direct endosymbiosis of CYANOBACTERIA. They are characterized by a mainly photosynthetic mode of nutrition; essentially unlimited growth at localized regions of cell divisions (MERISTEMS); cellulose within cells providing rigidity; the absence of organs of locomotion; absence of nervous and sensory systems; and an alternation of haploid and diploid generations.4-Chloromercuribenzenesulfonate: A cytotoxic sulfhydryl reagent that inhibits several subcellular metabolic systems and is used as a tool in cellular physiology.

Regulation of 2-carboxy-D-arabinitol 1-phosphate phosphatase: activation by glutathione and interaction with thiol reagents. (1/2188)

2-Carboxy-D-arabinitol 1-phosphate (CA1P) phosphatase de- grades CA1P, an inhibitor associated with the regulation of ribulose bisphosphate carboxylase/oxygenase in numerous plant species. CA1P phosphatase purified from Phaseolus vulgaris was partially inactivated by oxidizing conditions during dialysis in air-equilibrated buffer. Phosphatase activity could then be stimulated 1.3-fold by dithiothreitol and also by addition of reduced thioredoxin from Escherichia coli. These effects were enhanced synergistically by the positive effector, fructose 1, 6-bisphosphate (FBP). Most notably, CA1P phosphatase activity was stimulated up to 35-fold by glutathione, and was sensitive to the ratio of reduced (GSH) to oxidized (GSSG) forms. At concentrations of glutathione approximating measured levels in chloroplasts of P. vulgaris (5 mM total S), CA1P phosphatase exhibited >20-fold stimulation by a change in the redox status of glutathione from 60 to 100% GSH. This stimulation was augmented further by reduced E. coli thioredoxin. In contrast, FBP, which activates CA1P phosphatase under reducing conditions, was strongly inhibitory in the presence of GSSG. We propose that glutathione may have an appreciable role in the light/dark regulation of CA1P phosphatase in vivo. A model for the reversible activation of CA1P phosphatase by GSH was derived based upon the various responses of the enzyme's activity to a range of thiol reagents including N-ethylmaleimide, 5, 5'-dithiobis-(2-nitrobenzoic acid) and arsenite. These data indicate that the bean enzyme contains two physically distinct sets of thiol groups that are critical to its redox regulation.  (+info)

In vivo formation of Cu,Zn superoxide dismutase disulfide bond in Escherichia coli. (2/2188)

We have found that the in vivo folding of periplasmic Escherichia coli Cu,Zn superoxide dismutase is assisted by DsbA, which catalyzes the efficient formation of its single disulfide bond, whose integrity is essential to ensure full catalytic activity to the enzyme. In line with these findings, we also report that the production of recombinant Xenopus laevis Cu,Zn superoxide dismutase is enhanced when the enzyme is exported in the periplasmic space or is expressed in thioredoxin reductase mutant strains. Our data show that inefficient disulfide bond oxidation in the bacterial cytoplasm inhibits Cu,Zn superoxide dismutase folding in this cellular compartment.  (+info)

An intact sperm nuclear matrix may be necessary for the mouse paternal genome to participate in embryonic development. (3/2188)

We have been interested in determining the minimally required elements in the sperm head that are necessary in order for the paternal genome to participate in embryogenesis. We used an ionic detergent, mixed alkyltrimethylammonium bromide (ATAB), plus dithiothreitol (DTT) to remove the acrosome and almost all of the perinuclear theca, leaving only the sperm nucleus morphologically intact. We also tested the stability of the sperm nuclear matrix by the ability to form nuclear halos. Sperm nuclei washed in freshly prepared 0.5% ATAB + 2 mM DTT completely decondensed when extracted with salt, but nuclei washed in the same buffer that was 1 wk old, and then extracted with salt, produced nuclear halos, indicating stable nuclear matrices. When we treated sperm heads with freshly prepared ATAB+DTT and injected them into oocytes, none of the oocytes developed into live offspring. In contrast, sperm heads treated in the same way but with 1-wk-old ATAB+DTT solution could support development of about 30% of the oocytes to live offspring. Electron microscopy demonstrated that most of the perinuclear theca had been removed in both cases. These data suggest that at least in the mouse, the only component of the spermatozoa that is crucial for participation in embryologic development is the sperm nucleus with a stable nuclear matrix.  (+info)

A novel trans-complementation assay suggests full mammalian oocyte activation is coordinately initiated by multiple, submembrane sperm components. (4/2188)

To initiate normal embryonic development, an egg must receive a signal to become activated at fertilization. We here report that the ability of demembranated sperm heads to activate is abolished after incubation over the range 20-44 degreesC and is sensitive to reducing agents. On the basis of this observation, we have developed a microinjection-based, trans-complementation assay in order to dissect the heat-inactivated sperm-borne oocyte-activating factor(s) (SOAF). We demonstrate that the failure of heat-inactivated sperm heads to activate an egg is rescued by coinjection with dithiothreitol-solubilized SOAF from demembranated sperm heads. The solubilized SOAF (SOAFs) is trypsin sensitive and is liberated from demembranated heads in a temperature-dependent manner that inversely correlates with the ability of sperm heads to activate. This argues that SOAFs is a proteinaceous molecular species required to initiate activation. Injection of oocytes with mouse or hamster sperm cytosolic factors, but not SOAFs alone, induced resumption of meiosis, further suggesting that these cytosolic factors and SOAF are distinct. Collectively, these data strongly suggest that full mammalian oocyte activation is initiated by the coordinated action of one or more heat-sensitive protein constituents of the perinuclear matrix and at least one heat-stable submembrane component.  (+info)

Transforming growth factor-beta induces formation of a dithiothreitol-resistant type I/Type II receptor complex in live cells. (5/2188)

Transforming growth factor-beta (TGF-beta) binds to and signals via two serine-threonine kinase receptors, the type I (TbetaRI) and type II (TbetaRII) receptors. We have used different and complementary techniques to study the physical nature and ligand dependence of the complex formed by TbetaRI and TbetaRII. Velocity centrifugation of endogenous receptors suggests that ligand-bound TbetaRI and TbetaRII form a heteromeric complex that is most likely a heterotetramer. Antibody-mediated immunofluorescence co-patching of epitope-tagged receptors provides the first evidence in live cells that TbetaRI. TbetaRII complex formation occurs at a low but measurable degree in the absence of ligand, increasing significantly after TGF-beta binding. In addition, we demonstrate that pretreatment of cells with dithiothreitol, which inhibits the binding of TGF-beta to TbetaRI, does not prevent formation of the TbetaRI.TbetaRII complex, but increases its sensitivity to detergent and prevents TGF-beta-activated TbetaRI from phosphorylating Smad3 in vitro. This indicates that either a specific conformation of the TbetaRI. TbetaRII complex, disrupted by dithiothreitol, or direct binding of TGF-beta to TbetaRI is required for signaling.  (+info)

Gamma-Actinin, a new regulatory protein from rabbit skeletal muscle. I. Purification and characterization. (6/2188)

A new regulatory protein which we have designated as gamma-actinin has been isolated from native thin filaments of rabbit skeletal muscle. Depolymerized native thin filaments were fractionated by salting out with ammonium sulfate, and the precipitates obtained at 40--60% ammonium sulfate saturation were further subjected to DEAE-Sephadex and Sephadex G-200 column chromatography. The purified gamma-actinin was shown to have a chain weight of 35,000 daltons and had a strong inhibitory action on the polymerization of G-actin. The results of amino acid analysis indicated a unique amino acid composition of gamma-actinin as compared with other structural proteins of muscle. Non-polar and neutral amino acid residues were abundant. One cysteine residue was contained per one molecule of gamma-actinin and played a critical role in the maintenance of the inhibitory activity. Pelleting of gamma-actinin with F-actin showed that gamma-actinin binds to F-action.  (+info)

Phospholipid hydroperoxide cysteine peroxidase activity of human serum albumin. (7/2188)

Human serum albumin (HSA) reduced the phospholipid hydroperoxide, 1-palmitoyl-2-(13-hydroperoxy-cis-9, trans-11-octadecadienoyl)-l-3-phosphatidylcholine (PLPC-OOH) to the corresponding hydroxy-derivative with a high apparent affinity (Km=9. 23+/-0.95 microM). Removal of bound lipid during purification increased this activity. At physiological concentration, HSA reduced the phospholipid hydroperoxide in the absence of a cofactor. However, in the presence of a cofactor (reductant), the rate of the reaction was increased. All of the major aminothiols in plasma could act as reductants, the best being the most abundant, cysteine (Km=600+/-80 microM). For every nanomole of PLPC-OOH reduced by HSA, 1.26 nmol of cystine was formed, indicating a reaction stoichiometry of 1 mol PLPC-OOH to 2 mol cysteine. We used chemical modification to determine which amino acid residues on HSA were responsible for the activity. Oxidation of thiol group(s) by N-ethylmaleimide led to a reduction in the rate of activity, whereas reduction of thiols by either dithiothreitol or the angiotensin-converting enzyme inhibitor, captopril, increased the activity. Both N-ethylmaleimide-modified HSA and dithiothreitol-treated HSA exhibited increased apparent affinities for PLPC-OOH. For a range of preparations of albumin with different modifications, the activity on PLPC-OOH was dependent on the amount of free thiol groups on the albumin (correlation coefficient=0.91). Patients with lowered albumin concentrations after septic shock showed lowered total plasma thiol concentrations and decreased phospholipid hydroperoxide cysteine peroxidase (PHCPx) activities. These results therefore show for the first time that HSA exhibits PHCPx activity, and that the majority of the activity depends on the presence of reduced thiol group(s) on the albumin.  (+info)

Respiratory chain strongly oxidizes the CXXC motif of DsbB in the Escherichia coli disulfide bond formation pathway. (8/2188)

Escherichia coli DsbB has four essential cysteine residues, among which Cys41 and Cys44 form a CXXC redox active site motif and the Cys104-Cys130 disulfide bond oxidizes the active site cysteines of DsbA, the disulfide bond formation factor in the periplasm. Functional respiratory chain is required for the cell to keep DsbA oxidized. In this study, we characterized the roles of essential cysteines of DsbB in the coupling with the respiratory chain. Cys104 was found to form the inactive complex with DsbA under respiration-defective conditions. While DsbB, under normal aerobic conditions, is in the oxidized state, having two intramolecular disulfide bonds, oxidation of Cys104 and Cys130 requires the presence of Cys41-Cys44. Remarkably, the Cys41-Cys44 disulfide bond is refractory to reduction by a high concentration of dithiothreitol, unless the membrane is solubilized with a detergent. This reductant resistance requires both the respiratory function and oxygen, since Cys41-Cys44 became sensitive to the reducing agent when membrane was prepared from quinone- or heme-depleted cells or when a membrane sample was deaerated. Thus, the Cys41-Val-Leu-Cys44 motif of DsbB is kept both strongly oxidized and strongly oxidizing when DsbB is integrated into the membrane with the normal set of respiratory components.  (+info)

  • Dithiothreitol markedly increased the ligand binding affinity of angiotensin II (AII) receptor type II (AT 2 ) without affecting its antagonist selectivity in cultured ovarian granulosa cells, demonstrating that this AT 2 is of the dithiothreitol-sensitive type. (elsevier.com)
  • Dithiothreitol (DTT) effectively suppressed the phenylarsine oxide-inhibited cellular reductive capacity, but unexpectedly, enhanced As 2 O 3 -induced apoptosis in NB4 cells. (aspetjournals.org)
  • Due to air oxidation, DL-dithiothreitol (DTT) is a relatively unstable compound whose useful life can be extended by refrigeration and handling in an inert atmosphere. (24marketreports.com)
  • Dithiothreitol" is a descriptor in the National Library of Medicine's controlled vocabulary thesaurus, MeSH (Medical Subject Headings) . (harvard.edu)
  • We have developed an assay for PM redox activity, utilizing the reduction of oxygen by dithiothreitol which serves as an electron source. (cdc.gov)
  • Acid treatment of influenza A and B virus preparations followed by addition of dithiothreitol (DTT) and centrifugation through a sucrose cushion removes the HA1 subunit of hemagglutinin from virus. (nih.gov)
  • In consumption market, the global consumption value of DL-dithiothreitol (DTT) increases with the 4.55% average growth rate. (24marketreports.com)
  • To study and analyze the global DL-Dithiothreitol (DTT) consumption (value & volume) by key regions /countries, product type and application, history data from 2014 to 2018, and forecast to 2024. (24marketreports.com)
  • Dithiothreitol repairs up to 30% of DNA radicals, but an increase in the thiol concentration above 10 mM, even up to 1000 mM, does not further enhance the overall level of the repair process. (warwick.ac.uk)
  • According to this study, over the next five years the DL-Dithiothreitol (DTT) market will register a 2.5% CAGR in terms of revenue, the global market size will reach US$ 1080 million by 2024, from US$ 950 million in 2019. (24marketreports.com)
  • Effect of zinc and dithiothreitol (DTT) on LLER oligomerization. (nih.gov)
  • The effect of a thiol, dithiothreitol (DTT), on DNA radiolysis at cryogenic temperatures was investigated by the EPR method. (warwick.ac.uk)
  • Herein, we used low-dose pharmacological UPR inducers such as tunicamycin (TM) and dithiothreitol (DTT) to efficiently activate the IRE1-XBP-1 pathway in myeloma cells characterized by transcriptional expression increase in spliced XBP-1 and molecular chaperons, accompanied by significant differentiation and maturation of these myeloma cells, without concomitant cytotoxicity. (sigmaaldrich.com)
  • This graph shows the total number of publications written about "Dithiothreitol" by people in Harvard Catalyst Profiles by year, and whether "Dithiothreitol" was a major or minor topic of these publication. (harvard.edu)
  • With reducing action of DL-dithiothreitol (DTT), the downstream application industries will need more DL-dithiothreitol (DTT) products. (24marketreports.com)
  • High efficiency transformation by electroporation of Pichia pastoris pretreated with lithium acetate and dithiothreitol. (nih.gov)
  • International validation of a dithiothreitol (DTT)-based method to resolve the daratumumab interference with blood compatibility testing. (harvard.edu)
  • DL-Dithiothreitol Market also splits the market by region: Breakdown data in Chapter 4, 5, 6, 7 and 8. (24marketreports.com)
  • The key manufacturers covered in DL-Dithiothreitol Market : Breakdown data in in Chapter 3. (24marketreports.com)
  • In addition, DL-Dithiothreitol Market discusses the key drivers influencing market growth, opportunities, the challenges and the risks faced by key manufacturers and the market as a whole. (24marketreports.com)
  • DL-Dithiothreitol Market presents a comprehensive overview, market shares, and growth opportunities of DL-Dithiothreitol (DTT) market by product type, application, key manufacturers and key regions and countries. (24marketreports.com)
  • Chisholm KM, Getsinger D, Vaughan W, Hwang PH, Banaei N. Pretreatment of sinus aspirates with dithiothreitol improves yield of fungal cultures in patients with chronic sinusitis. (harvard.edu)