Search results for "disulfide"

Oxidative damage to mitochondrial DNA and glutathione oxidation in apoptosis: studiesin vivoandin vitro

1999

Free radicals may be involved in apoptosis although this is the subject of some controversy. Furthermore, the source of free radicals in apoptotic cells is not certain. The aim of this study was to elucidate the role of oxidative stress in the induction of apoptosis in serum-deprived fibroblast cultures and in weaned lactating mammary glands as in vitro and in vivo experimental models, respectively. Oxidative damage to mtDNA is higher in apoptotic cells than in controls. Oxidized glutathione (GSSG) levels in mitochondria from lactating mammary gland are also higher in apoptosis. There is a direct relationship between mtDNA damage and the GSSG/reduced glutathione (GSH) ratio. Furthermore, wh…

Key Disulfide Bonds in an Insect Hormone Binding Protein: cDNA Cloning of a Juvenile Hormone Binding Protein of Heliothis virescens and Ligand Bindin…

1995

The hemolymph juvenile hormone binding protein (JHBP) from the early fifth instar larvae of Heliothis virescens (Lepidoptera, Noctuidae) has been purified, and three cDNA clones for this protein have been isolated from a fat body cDNA library constructed in bacteriophage λZAP XR. The deduced amino acid sequence of the full-length clone predicts a mature protein consisting of 224 residues, a molecular mass of 24 976 Da, and a p/ of 5.29. Comparison of the amino acid sequence to that of the previously described JHBP from Manduca sexta shows 51 % overall identity with highly conserved N- and C-terminal regions. One of the three clones bound photoactivatable analogs of juvenile hormones with mu…

Assembly of the Major and the Minor Capsid Protein of Human Papillomavirus Type 33 into Virus-like Particles and Tubular Structures in Insect Cells

1994

Native virions of human papillomaviruses (HPV) can be isolated from genital lesions only in very limited amounts. Recent studies have shown that virus-like particles can be obtained by expression of the capsid proteins using vaccinia virus recombinants or the baculovirus system. We now present the first detailed characterization of virus-like particles of a human papillomavirus associated with malignant genital lesions, HPV-33, produced in high yield using the baculovirus expression system. Assembly of the major capsid protein L1 alone or together with the minor capsid protein L2 has been obtained. Both spherical virus-like particles of 50-60 nm diameter and tubular structures of either 25-…

Preliminary Results on the Use of Leather Chrome Shavings for Air Passive Sampling

2012

A new passive sampler based on low-density polyethylene (LDPE) layflat tube filled with chrome shavings from tannery waste residues was evaluated to determine volatile organic compounds (VOCs) in indoor and outdoor areas. VOCs were directly determined by head space-gas chromatography-mass spectrometry (HS-GC-MS) without any pretreatment of the sampler and avoiding the use of solvents. Limit of detection values ranging from 20 to 75 ng sampler−1and good repeatability values were obtained for VOCs under study with relative standard deviation values from 2.8 to 9.6% except for carbon disulfide for which it was 22.5%. The effect of the amount of chrome shavings per sampler was studied and resul…

Reactions of azoesters and dimethyl acetylenedicarboxylate with 3-methyl-1,2,4-triazole-5-thione

1991

The addition of dimethyl acetylenedicarboxylate to 3-methyl-1,2,4-triazole-5-thione (1), both in alcoholic medium and in inert solvents, has been investigated. When 1 was allowed to react with diethyl azodicarboxylate a disulfide 5 was obtained.

A kinetic model for the oxidation of benzenethiol catalyzed by the [MoVIO2(O2CC(S)(C6H5)2)2]2− complex intercalated in a Zn(II)–Al(III) layered doubl…

2009

Abstract The heterogeneous oxidation of benzenethiol catalyzed by the dianionic bis(2-sulfanyl-2,2-diphenylethanoxycarbonyl) dioxomolybdate (VI) complex intercalated into a Zn(II)–Al(III) layered double hydroxide (LDH) host have been investigated under aerobic conditions. The kinetics of the system has been analysed in detail. In ethanol, the benzenethiol is cleanly oxidized to diphenyl disulfide in the acidic media provided by the protonic resin Amberlite IR-120(H). The reaction is second-order in benzenethiol, and the apparent rate coefficient has been found to be proportional to the catalyst weight and inversely proportional to the initial concentration of the substrate. A catalytic cycl…

Electrochemical Formation of 3,5-Diimido-1,2-dithiolanes by Dehydrogenative Coupling

2018

A synthetic approach to the cyclic disulfide moiety of 3,5-diimido-1,2-dithiolane derivatives starting with readily available precursors including the electrochemical coupling of dithioanilides is developed. The electrochemical key step provides sustainable synthetic access in high yields, using a very simple electrolysis setup.

Of Thiols and Disulfides: Methods for Chemoselective Formation of Asymmetric Disulfides in Synthetic Peptides and Polymers.

2018

In protein or peptide chemistry, thiols are frequently chosen as a chemical entity for chemoselective modification reactions. Although it is a well-established methodology to address cysteines and homocysteines in aqueous media to form S-C bonds, possibilities for the chemoselective formation of asymmetric disulfides have been less approached. Focusing on bioreversibility in conjugation chemistry, the formation of disulfide bonds is highly desirable for the attachment of thiol-containing bioactive agents to proteins or in cross-linking reactions, because disulfide bonds can combine stability in blood with degradability inside cells. In this Concept article, recent approaches in the field of…

Overcoming the Insolubility of Molybdenum Disulfide Nanoparticles through a High Degree of Sidewall Functionalization Using Polymeric Chelating Ligan…

2006

Endoplasmic Reticulum Chaperones in Viral Infection: Therapeutic Perspectives

2021

SUMMARY Viruses are intracellular parasites that subvert the functions of their host cells to accomplish their infection cycle. The endoplasmic reticulum (ER)-residing chaperone proteins are central for the achievement of different steps of the viral cycle, from entry and replication to assembly and exit. The most abundant ER chaperones are GRP78 (78-kDa glucose-regulated protein), GRP94 (94-kDa glucose-regulated protein), the carbohydrate or lectin-like chaperones calnexin (CNX) and calreticulin (CRT), the protein disulfide isomerases (PDIs), and the DNAJ chaperones. This review will focus on the pleiotropic roles of ER chaperones during viral infection. We will cover their essential role …