Functional properties of the two redox-active sites in yeast protein disulphide isomerase in Vitro and in Vivo 1 1Edited by G. Von Heijne

1999 ◽  
Vol 286 (4) ◽  
pp. 1229-1239 ◽  
Author(s):  
Vibeke Westphal ◽  
Nigel J Darby ◽  
Jakob R Winther
Keyword(s):  
Functional Properties ◽  
Active Sites ◽  
Yeast Protein ◽  
Protein Disulphide Isomerase ◽  
Redox Active

Action of Thioglycosides of 1,2,4-Triazoles and Imidazoles on the Oxidative Stress and Glycosidases in Mice with Molecular Docking

2019 ◽  
Vol 16 (6) ◽  
pp. 696-710
Author(s):  
Mahmoud Balbaa ◽  
Doaa Awad ◽  
Ahmad Abd Elaal ◽  
Shimaa Mahsoub ◽  
Mayssaa Moharram ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Molecular Docking ◽  
Active Sites ◽  
Biological Activities ◽  
Imidazole Ring ◽  
Quantitative Structure Activity Relationship ◽  
Binding Interaction ◽  
Qsar Study

Background: ,2,3-Triazoles and imidazoles are important five-membered heterocyclic scaffolds due to their extensive biological activities. These products have been an area of growing interest to many researchers around the world because of their enormous pharmaceutical scope. Methods: The in vivo and in vitro enzyme inhibition of some thioglycosides encompassing 1,2,4- triazole N1, N2, and N3 and/or imidazole moieties N4, N5, and N6. The effect on the antioxidant enzymes (superoxide dismutase, glutathione S-transferase, glutathione peroxidase and catalase) was investigated as well as their effect on α-glucosidase and β-glucuronidase. Molecular docking studies were carried out to investigate the mode of the binding interaction of the compounds with α- glucosidase and β -glucuronidase. In addition, quantitative structure-activity relationship (QSAR) investigation was applied to find out the correlation between toxicity and physicochemical properties. Results: The decrease of the antioxidant status was revealed by the in vivo effect of the tested compounds. Furthermore, the in vivo and in vitro inhibitory effects of the tested compounds were clearly pronounced on α-glucosidase, but not β-glucuronidase. The IC50 and Ki values revealed that the thioglycoside - based 1,2,4-triazole N3 possesses a high inhibitory action. In addition, the in vitro studies demonstrated that the whole tested 1,2,4-triazole are potent inhibitors with a Ki magnitude of 10-6 and exhibited a competitive type inhibition. On the other hand, the thioglycosides - based imidazole ring showed an antioxidant activity and exerted a slight in vivo stimulation of α-glucosidase and β- glucuronidase. Molecular docking proved that the compounds exhibited binding affinity with the active sites of α -glucosidase and β-glucuronidase (docking score ranged from -2.320 to -4.370 kcal/mol). Furthermore, QSAR study revealed that the HBD and RB were found to have an overall significant correlation with the toxicity. Conclusion: These data suggest that the inhibition of α-glucosidase is accompanied by an oxidative stress action.

scholarly journals Arsenic Directly Binds to and Activates the Yeast AP-1-Like Transcription Factor Yap8

2015 ◽  
Vol 36 (6) ◽  
pp. 913-922 ◽  
Author(s):  
Nallani Vijay Kumar ◽  
Jianbo Yang ◽  
Jitesh K. Pillai ◽  
Swati Rawat ◽  
Carlos Solano ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Transcriptional Activation ◽  
Transcriptional Response ◽  
Transcriptional Regulator ◽  
Yeast Protein ◽  
Content Type ◽  
Arsenic Tolerance ◽  
Arsenic Sensing

The AP-1-like transcription factor Yap8 is critical for arsenic tolerance in the yeastSaccharomyces cerevisiae. However, the mechanism by which Yap8 senses the presence of arsenic and activates transcription of detoxification genes is unknown. Here we demonstrate that Yap8 directly binds to trivalent arsenite [As(III)]in vitroandin vivoand that approximately one As(III) molecule is bound per molecule of Yap8. As(III) is coordinated by three sulfur atoms in purified Yap8, and our genetic and biochemical data identify the cysteine residues that form the binding site as Cys132, Cys137, and Cys274. As(III) binding by Yap8 does not require an additional yeast protein, and Yap8 is regulated neither at the level of localization nor at the level of DNA binding. Instead, our data are consistent with a model in which a DNA-bound form of Yap8 acts directly as an As(III) sensor. Binding of As(III) to Yap8 triggers a conformational change that in turn brings about a transcriptional response. Thus, As(III) binding to Yap8 acts as a molecular switch that converts inactive Yap8 into an active transcriptional regulator. This is the first report to demonstrate how a eukaryotic protein couples arsenic sensing to transcriptional activation.

scholarly journals Bioinspired organometallic chemistry

2002 ◽  
Vol 74 (1) ◽  
pp. 115-122 ◽  
Author(s):  
Lanny S. Liebeskind ◽  
Jiri Srogl ◽  
Cecile Savarin ◽  
Concepcion Polanco
Keyword(s):  
Organometallic Chemistry ◽  
Refractory Metal ◽  
Redox Active ◽  
The Stability ◽  
New Procedures ◽  
Sulfur Containing ◽  
Insight Into

Given the stability of the bond between a mercaptide ligand and various redox-active metals, it is of interest that Nature has evolved significant metalloenzymatic processes that involve key interactions of sulfur-containing functionalities with metals such as Ni, Co, Cu, and Fe. From a chemical perspective, it is striking that these metals can function as robust biocatalysts in vivo, even though they are often "poisoned" as catalysts in vitro through formation of refractory metal thiolates. Insight into the nature of this chemical discrepancy is under study in order to open new procedures in synthetic organic and organometallic chemistry.

scholarly journals In Vitro and In Vivo Inhibition of the 2 Active Sites of ACE by Omapatrilat, a Vasopeptidase Inhibitor

Hypertension ◽  
2000 ◽  
Vol 35 (6) ◽  
pp. 1226-1231 ◽  
Author(s):  
Michel Azizi ◽  
Christine Massien ◽  
Annie Michaud ◽  
Pierre Corvol
Keyword(s):  
Active Sites ◽  
Vasopeptidase Inhibitor

TrioGEF1 controls Rac- and Cdc42-dependent cell structures through the direct activation of rhoG

2000 ◽  
Vol 113 (4) ◽  
pp. 729-739 ◽  
Author(s):  
A. Blangy ◽  
E. Vignal ◽  
S. Schmidt ◽  
A. Debant ◽  
C. Gauthier-Rouviere ◽  
...  
Keyword(s):  
Rho Gtpases ◽  
Active Sites ◽  
Dominant Negative ◽  
Signaling Cascade ◽  
Microtubule Network ◽  
Cell Structures ◽  
Dependent Cell

Rho GTPases regulate the morphology of cells stimulated by extracellular ligands. Their activation is controlled by guanine exchange factors (GEF) that catalyze their binding to GTP. The multidomain Trio protein represents an emerging class of Ρ regulators that contain two GEF domains of distinct specificities. We report here the characterization of Rho signaling pathways activated by the N-terminal GEF domain of Trio (TrioD1). In fibroblasts, TrioD1 triggers the formation of particular cell structures, similar to those elicited by RhoG, a GTPase known to activate both Rac1 and Cdc42Hs. In addition, the activity of TrioD1 requires the microtubule network and relocalizes RhoG at the active sites of the plasma membrane. Using a classical in vitro exchange assay, TrioD1 displays a higher GEF activity on RhoG than on Rac1. In fibroblasts, expression of dominant negative RhoG mutants totally abolished TrioD1 signaling, whereas dominant negative Rac1 and Cdc42Hs only led to partial and complementary inhibitions. Finally, expression of a Rho Binding Domain that specifically binds RhoG(GTP) led to the complete abolition of TrioD1 signaling, which strongly supports Rac1 not being activated by TrioD1 in vivo. These data demonstrate that Trio controls a signaling cascade that activates RhoG, which in turn activates Rac1 and Cdc42Hs.

scholarly journals A Mini Review on Antidiabetic Properties of Fermented Foods

Nutrients ◽  
2018 ◽  
Vol 10 (12) ◽  
pp. 1973 ◽  
Author(s):  
Bhagavathi Sivamaruthi ◽  
Periyanaina Kesika ◽  
Mani Prasanth ◽  
Chaiyavat Chaiyasut
Keyword(s):  
Functional Properties ◽  
Antioxidant Properties ◽  
Treatment Strategies ◽  
In Vivo Studies ◽  
Fermented Foods ◽  
Gastrointestinal Health ◽  
Randomized Controlled Clinical Trials ◽  
The Government

In general, fermented foods (FFs) are considered as functional foods. Since the awareness about the health benefits of FFs has increased, the consumption of FF also improved significantly in recent decades. Diabetes is one of the leading threats of the health span of an individual. The present manuscript details the general methods of the production of FFs, and the results of various studies (in vitro, in vivo, and clinical studies) on the antidiabetic properties of FFs. The fermentation method and the active microbes involved in the process play a crucial role in the functional properties of FFs. Several in vitro and in vivo studies have been reported on the health-promoting properties of FFs, such as anti-inflammation, anticancer, antioxidant properties, improved cognitive function and gastrointestinal health, and the reduced presence of metabolic disorders. The studies on the functional properties of FFs by randomized controlled clinical trials using human volunteers are very limited for several reasons, including ethical reasons, safety concerns, approval from the government, etc. Several scientific teams are working on the development of complementary and alternative medicines to improve the treatment strategies for hyperglycemia.

scholarly journals Discovery of a dual inhibitor of NQO1 and GSTP1 for treating glioblastoma

2020 ◽  
Vol 13 (1) ◽  
Author(s):  
Kecheng Lei ◽  
Xiaoxia Gu ◽  
Alvaro G. Alvarado ◽  
Yuhong Du ◽  
Shilin Luo ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Crystal Structures ◽  
Active Sites ◽  
Redox Homeostasis ◽  
Growth Factor Receptor ◽  
Quinone Oxidoreductase ◽  
Cancer Proliferation ◽  
Dual Inhibitor

Abstract Background Glioblastoma (GBM) is a universally lethal tumor with frequently overexpressed or mutated epidermal growth factor receptor (EGFR). NADPH quinone oxidoreductase 1 (NQO1) and glutathione-S-transferase Pi 1 (GSTP1) are commonly upregulated in GBM. NQO1 and GSTP1 decrease the formation of reactive oxygen species (ROS), which mediates the oxidative stress and promotes GBM cell proliferation. Methods High-throughput screen was used for agents selectively active against GBM cells with EGFRvIII mutations. Co-crystal structures were revealed molecular details of target recognition. Pharmacological and gene knockdown/overexpression approaches were used to investigate the oxidative stress in vitro and in vivo. Results We identified a small molecular inhibitor, “MNPC,” that binds to both NQO1 and GSTP1 with high affinity and selectivity. MNPC inhibits NQO1 and GSTP1 enzymes and induces apoptosis in GBM, specifically inhibiting the growth of cell lines and primary GBM bearing the EGFRvIII mutation. Co-crystal structures between MNPC and NQO1, and molecular docking of MNPC with GSTP1 reveal that it binds the active sites and acts as a potent dual inhibitor. Inactivation of both NQO1 and GSTP1 with siRNA or MNPC results in imbalanced redox homeostasis, leading to apoptosis and mitigated cancer proliferation in vitro and in vivo. Conclusions Thus, MNPC, a dual inhibitor for both NQO1 and GSTP1, provides a novel lead compound for treating GBM via the exploitation of specific vulnerabilities created by mutant EGFR.

Organic selenium derived from chelation of soybean peptide-selenium and its functional properties in vitro and in vivo

2019 ◽  
Vol 10 (8) ◽  
pp. 4761-4770 ◽  
Author(s):  
Qianwen Ye ◽  
Xiaoping Wu ◽  
Xinyuan Zhang ◽  
Shaoyun Wang
Keyword(s):  
Antioxidant Activity ◽  
Functional Properties ◽  
Soybean Protein ◽  
Protein Isolate ◽  
Soybean Protein Isolate ◽  
Organic Selenium

The preparation and characterization of a soybean protein isolate peptide-Se chelate with remarkably antioxidant activity in vitro and in vivo.

A Proteasome Specific Binding Assay for Quantitation of Constitutive and Immunoproteasome Active Sites.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 2472-2472
Author(s):  
Mark K. Bennett ◽  
Monette A. Aujay ◽  
Tonia J. Buchholz ◽  
Susan D. Demo ◽  
Guy J. Laidig ◽  
...  
Keyword(s):  
Active Sites ◽  
Antigen Processing ◽  
Specific Binding ◽  
Peripheral Blood Mononuclear ◽  
Peptide Substrates ◽  
Enzyme Preparations ◽  
Proteolytic Activities ◽  
Fluorogenic Peptide

Abstract The ubiquitin-proteasome pathway constitutes a major intracellular system for protein degradation. Substrates for this pathway include misfolded or unassembled proteins as well as short-lived regulatory proteins that play key roles in signaling and proliferative pathways. The majority of cell types express the standard, or “constitutive”, form of the proteasome, while cells of the immune system also express the immunoproteasome, a form of the proteasome that contributes to class I major histocompatibility complex restricted antigen processing. Non-immune cells can also express immunoproteasome in response to interferon gamma exposure. The immunoproteasome retains the same structural subunits as the constitutive proteasome but has three different catalytic subunits. The catalytic activities of both forms of the proteasome have been traditionally characterized with purified enzyme preparations and fluorogenic peptide substrates. Such fluorogenic peptide substrates suffer from two characteristics that limit their utility in measuring proteasome activities in complex cell or tissue lysates: 1) they cannot distinguish proteasome activities from other proteolytic activities within the lysate; and 2) they can not distinguish between constitutive and immunoproteasome activities. We have developed an ELISA-based proteasome-specific binding (PSB) assay that can detect and quantify the chymotryptic-like proteasome active sites of the beta-5 constitutive proteasome subunit and the LMP7 immunoproteasome subunit. The assay utilizes a biotin-modified peptide epoxyketone probe that covalently and irreversibly interacts with the active site threonine present in catalytic proteasome subunits. Once bound to the probe, the labeled subunits are recovered on streptavidin-conjugated beads and detected with subunit-specific antibodies. The PSB assay is both quantitative and sensitive. We have demonstrated that the assay is capable of measuring constitutive proteasome and immunoproteasome binding activity in human whole blood and peripheral blood mononuclear cell preparations, respectively. In experiments with the epoxyketone-based proteasome inhibitor PR-171, the dose response for inhibition of the PSB assay is equivalent to that measured with a conventional fluorogenic peptide proteasome substrate. In addition, the PSB assay can effectively measure the level of PR-171 mediated inhibition of both the constitutive and immunoproteasome in the RPMI-8226 multiple myeloma cell line that co-expresses both proteasome types. Thus, the PSB assay overcomes the limitations of conventional fluorogenic substrate-based proteasome activity assays when applied to cell or tissue lysates that contain multiple proteolytic activities or mixtures of constitutive and immunoproteasomes. Potential applications of the PSB assay include the measurement of the pharmacodynamic response to proteasome inhibitors and the evaluation of constitutive vs. immunoproteasome selectivity of inhibitors both in vitro and in vivo.

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