Search results for "Disulfide"
showing 10 items of 171 documents
Verwertbarkeit verschiedener Cysteinderivate bei langfristiger parenteraler Ernährung
1989
Utilization of cysteine derivatives for parenteral nutrition was established by means of nitrogen balance of growing rats. N,N-bis-acetylcystine and bisacetyl-glycyl-cystine were not utilized as substrates. N-acetylcysteine, glutathione disulfide, and L-thiazolidine-(4)-carboxylic acid gave evidence as suitable cysteine sources for parenteral nutrition.
Regulation of tumour cell sensitivity to TNF-induced oxidative stress and cytotoxicity: Role of glutathione
1998
Glutathione (GSH) and the rate of cellular proliferation determine tumour cell sensitivity to tumour necrosis factor (TNF). Buthionine sulphoximine (BSO), a selective inhibitor of GSH synthesis, inhibits tumour growth and increases recombinant human TNF (rhTNF)-alpha cytoxicity in vitro. Administration of sublethal doses of rhTNF-alpha to Ehrlich ascites-tumour (EAT)-bearing mice induces oxidative stress (as measured by increases in intracellular peroxide levels, O2.- generation and mitochondrial GSSG). ATP-induced selective GSH depletion, when combined with rhTNF-alpha administration, affords a 61% inhibition of tumour growth and results in a significant extent of host survival. Administra…
Identification of ERp29, an endoplasmic reticulum lumenal protein, as a new member of the thyroglobulin folding complex.
2002
Folding and post-translational modification of the thyroid hormone precursor, thyroglobulin (Tg), in the endoplasmic reticulum (ER) of the thyroid epithelial cells is facilitated by several molecular chaperones and folding enzymes, such as BiP, GRP94, calnexin, protein disulfide isomerase, ERp72, and others. They have been shown to associate simultaneously and/or sequentially with Tg in the course of its maturation, thus forming large heterocomplexes in the ER of thyrocytes. Here we present evidence that such complexes include a novel member, an ER-resident lumenal protein, ERp29, which is present in all mammalian tissues with exceptionally high levels of expression in the secretory cells. …
The protease domain of procollagen C-proteinase (BMP1) lacks substrate selectivity, which is conferred by non-proteolytic domains.
2007
Abstract Procollagen C-proteinase (PCP) removes the C-terminal pro-peptides of procollagens and also processes other matrix proteins. The major splice form of the PCP is termed BMP1 (bone morphogenetic protein 1). Active BMP1 is composed of an astacin-like protease domain, three CUB (complement, sea urchin Uegf, BMP1) domains and one EGF-like domain. Here we compare the recombinant human full-length BMP1 with its isolated proteolytic domain to further unravel the functional influence of the CUB and EGF domains. We show that the protease domain alone cleaves truncated procollagen VII within the short telopeptide region into fragments of similar size as the full-length enzyme does. However, u…
Disulfide stress: a novel type of oxidative stress in acute pancreatitis.
2013
Glutathione oxidation and protein glutathionylation are considered hallmarks of oxidative stress in cells because they reflect thiol redox status in proteins. Our aims were to analyze the redox status of thiols and to identify mixed disulfides and targets of redox signaling in pancreas in experimental acute pancreatitis as a model of acute inflammation associated with glutathione depletion. Glutathione depletion in pancreas in acute pancreatitis is not associated with any increase in oxidized glutathione levels or protein glutathionylation. Cystine and homocystine levels as well as protein cysteinylation and γ-glutamyl cysteinylation markedly rose in pancreas after induction of pancreatitis…
Expression and glycosylation studies of human FGF receptor 4
2001
Fibroblast growth factor receptor subtype 4 (FGFR4) has been shown to have special activation properties and just one splicing form, unlike the other FGFRs. FGFR4 overexpression is correlated with breast cancer and therefore FGFR4 is a target for drug design. Our aim is to overexpress high amounts of homogeneous FGFR4 extracellular domain (FGFR4ed) for structural studies. We show that baculovirus-insect cell-expressed FGFR4ed is glycosylated on three (N88, N234, and N266) of the six possible N-glycosylation sites but is not O-glycosylated. The deglycosylated triple mutant was expressed and had binding properties similar to those of glycosylated FGFR4ed, but was still heterogeneous. Large am…
Identification of disulphide bonds in the refolding of bovine pancreatic RNase A
1996
Background: Comprehension of the rules that govern the folding process is still far from satisfactory, though it is nevertheless clear that all the information required to define the folding is encoded in the amino acid sequence. In proteins that contain disulphide bonds, folding is associated with disulphide bond formation. Protein species with different numbers of disulphides tend to accumulate during the process; these species can be trapped in a stable form, by quenching any remaining free SH groups, and then characterized in order to identify the disulphide bonds formed. Results The refolding pathway of reduced and denatured RNase A has been studied using mass spectrometric strategies …
Ex vivo emission of volatile organic compounds from gastric cancer and non-cancerous tissue
2018
The presence of certain volatile organic compounds (VOCs) in the breath of patients with gastric cancer has been reported by a number of research groups; however, the source of these compounds remains controversial. Comparison of VOCs emitted from gastric cancer tissue to those emitted from non-cancerous tissue would help in understanding which of the VOCs are associated with gastric cancer and provide a deeper knowledge on their generation. Gas chromatography with mass spectrometric detection (GC-MS) coupled with head-space needle trap extraction (HS-NTE) as the pre-concentration technique, was used to identify and quantify VOCs released by gastric cancer and non-cancerous tissue samples c…
Substrate impact on the thickness dependence of vibrational and optical properties of large area $MoS_2$ produced by gold-assisted exfoliation
2021
The gold-assisted exfoliation is a very effective method to produce large-area ($cm^2$-scale) membranes of molybdenum disulfide ($MoS_2$) for electronics. However, the strong $MoS_2/Au$ interaction, beneficial for the exfoliation process, has a strong impact on the vibrational and light emission properties of $MoS_2$. Here, we report an atomic force microscopy (AFM), micro-Raman ($\mu-R$) and micro-Photoluminescence ($\mu-PL$) investigation of $MoS_2$ with variable thickness exfoliated on Au and subsequently transferred on an $Al_2O_3/Si$ substrate. The $E_{2g}$ - $A_{1g}$ vibrational modes separation $\Delta\mu$ (typically used to estimate $MoS_2$ thickness) exhibits an anomalous large val…
Age-dependent regulation of antioxidant genes by p38α MAPK in the liver
2018
p38α is a redox sensitive MAPK activated by pro-inflammatory cytokines and environmental, genotoxic and endoplasmic reticulum stresses. The aim of this work was to assess whether p38α controls the antioxidant defense in the liver, and if so, to elucidate the mechanism(s) involved and the age-related changes. For this purpose, we used liver-specific p38α-deficient mice at two different ages: young-mice (4 months-old) and old-mice (24 months-old). The liver of young p38α knock-out mice exhibited a decrease in GSH levels and an increase in GSSG/GSH ratio and malondialdehyde levels. However, old mice deficient in p38α had higher hepatic GSH levels and lower GSSG/GSH ratio than young p38α knock-…