scholarly journals The Metalloid Reductase of Pseudomonas Moravenis Stanleyae Conveys Nanoparticle Mediated Metalloid Tolerance

2018 ◽  
Author(s):  
Richard Nemeth ◽  
Mackenzie Neubert ◽  
Thomas Ni ◽  
Christopher J. Ackerson
Keyword(s):  
Structural Analysis ◽  
Substrate Specificity ◽  
Glutathione Reductase ◽  
Cell Lines ◽  
Bacterial Cell ◽  
Binding Pocket ◽  
Oxidized Glutathione ◽  
Se Nanoparticles ◽  
In Cells

In the present work we have identified a glutathione reductase like metalloid reductase (GRLMR) responsible for mediating selenite tolerance in <i>Pseudomonas moravenis</i> stanleyae through the enzymatic generation of Se(0) nanoparticles. This enzyme has an unprecedented substrate specificity for selenodiglutathione (K<sub>m</sub>= 336 μM) over oxidized glutathione (K<sub>m</sub>=8.22 mM). This enzyme was able to induce selenite tolerance in foreign bacterial cell lines by increasing the IC<sub>90</sub> for selenite from 1.9 mM in cell lacking the GRLMR gene to 21.3 mM for cells containing the GRLMR gene. It was later confirmed by STEM and EDS that Se nanoparticles were absent in control cells and present in cells expressing GRLMR. Structural analysis suggests the lack of a sulfur residue in the substrate/product binding pocket may be responsible for this unique substrate specificity.

scholarly journals The Metalloid Reductase of Pseudomonas Moravenis Stanleyae Conveys Nanoparticle Mediated Metalloid Tolerance

2018 ◽  
Author(s):  
Richard Nemeth ◽  
Mackenzie Neubert ◽  
Thomas Ni ◽  
Christopher J. Ackerson
Keyword(s):  
Structural Analysis ◽  
Substrate Specificity ◽  
Glutathione Reductase ◽  
Cell Lines ◽  
Bacterial Cell ◽  
Binding Pocket ◽  
Oxidized Glutathione ◽  
Se Nanoparticles ◽  
In Cells

In the present work we have identified a glutathione reductase like metalloid reductase (GRLMR) responsible for mediating selenite tolerance in <i>Pseudomonas moravenis</i> stanleyae through the enzymatic generation of Se(0) nanoparticles. This enzyme has an unprecedented substrate specificity for selenodiglutathione (K<sub>m</sub>= 336 μM) over oxidized glutathione (K<sub>m</sub>=8.22 mM). This enzyme was able to induce selenite tolerance in foreign bacterial cell lines by increasing the IC<sub>90</sub> for selenite from 1.9 mM in cell lacking the GRLMR gene to 21.3 mM for cells containing the GRLMR gene. It was later confirmed by STEM and EDS that Se nanoparticles were absent in control cells and present in cells expressing GRLMR. Structural analysis suggests the lack of a sulfur residue in the substrate/product binding pocket may be responsible for this unique substrate specificity.

scholarly journals Genome Mining, Phylogenetic and Structural Analysis of Bacterial Nitrilases for the Biodegradation of Nitrile Compounds

2021 ◽  
Author(s):  
Richa Salwan ◽  
Vivek Sharma ◽  
Surajit Das
Keyword(s):  
Structural Analysis ◽  
Substrate Specificity ◽  
Active Site ◽  
Structural Information ◽  
Genome Mining ◽  
Binding Pocket ◽  
Catalytic Triad ◽  
Vital Role ◽  
Active Site Residues ◽  
Motif Analysis

Abstract Microbial nitrilases play vital role in biodegradation of nitrile-containing contaminants in pollutant and effluents treatments in chemical and textile industries as well as the biosynthesis of IAA from tryptophan in plants. However, the lack of structural information hinders the correlation of its activity and substrate specificity. Here, we have identified bacterial genomes for nitrilases bearing unassigned functions including hypothetical, uncharacterized, or putative role. The genomic annotations revealed four predicted nitrilases encoding genes as uncharacterized subgroup of the nitrilase superfamily. Further, the annotation of these nitrilases revealed relatedness with nitrilase hydratases and cyanoalanine hydratases. The characterization of motif analysis of these protein sequences, predicted a single motif of 20-28 aa, and glutamate (E), lysine (K) and cysteine (C) residues as a part of catalytic triad along with several active site residues. The structural analysis of the modeled nitrilases revealed geometrical and close conformation of α-helices and β-sheets arranged in a sandwich structure. The catalytic residues constituted the substrate binding pocket and exhibited the wide nitrile substrate spectra for both aromatic and aliphatic nitriles containing compounds. The aromatic amino acid residues Y159 in active site were predicted to show importance for substrate specificity. The substitution of non-aromatic alanine residue in place of Y159 completely disrupted the catalytic activity for indole-3-acetonitrile. The present study reports several uncharacterized nitrilases which have not been reported so far for their role in the biodegradation of pollutants, xenobiotics which could find applications in industries.

Glutathione Reductase Turned into Trypanothione Reductase:  Structural Analysis of an Engineered Change in Substrate Specificity†,‡

Biochemistry ◽  
1997 ◽  
Vol 36 (21) ◽  
pp. 6437-6447 ◽  
Author(s):  
Vincent S. Stoll ◽  
Sarah J. Simpson ◽  
R. Luise Krauth-Siegel ◽  
Christopher T. Walsh ◽  
Emil F. Pai
Keyword(s):  
Structural Analysis ◽  
Substrate Specificity ◽  
Glutathione Reductase ◽  
Trypanothione Reductase

Absence of temporal ordering of apoptotic features in heat-shock treated leukemia and lymphoma cell lines

1996 ◽  
Vol 54 ◽  
pp. 758-759
Author(s):  
D. W. Fairbain ◽  
M.D. Standing ◽  
K.L. O'Neill
Keyword(s):  
Heat Shock ◽  
Cell Lines ◽  
Chromatin Condensation ◽  
Membrane Integrity ◽  
Resistant Cell ◽  
Membrane Blebbing ◽  
Late Loss ◽  
Induced Apoptosis ◽  
Dying Cells ◽  
In Cells

Apoptosis is a genetically defined response to physiological stimuli that results in cellular suicide. Features common to apoptotic cells include chromatin condensation, oligonucleosomal DNA fragmentation, membrane blebbing, nuclear destruction, and late loss of ability to exclude vital dyes. These characteristics contrast markedly from pathological necrosis, in which membrane integrity loss is demonstrated early, and other features of apoptosis, which allow a non-inflammatory removal of dead and dying cells, are absent. Using heat shock-induced apoptosis as a model for examining stress response in cells, we undertook to categorize a variety of human leukemias and lymphomas with regard to their response to heat shock. We were also interested in determining whether a common temporal order was followed in cells dying by apoptosis. In addition, based on our previous results, we investigated whether increasing heat load resulted in increased apoptosis, with particular interest in relatively resistant cell lines, or whether the mode of death changed from apoptosis to necrosis.

scholarly journals Altering the Substrate Specificity of Acetyl-CoA Synthetase by Rational Mutagenesis of the Carboxylate Binding Pocket

2019 ◽  
Vol 8 (6) ◽  
pp. 1325-1336 ◽  
Author(s):  
Naazneen Sofeo ◽  
Jason H. Hart ◽  
Brandon Butler ◽  
David J. Oliver ◽  
Marna D. Yandeau-Nelson ◽  
...  
Keyword(s):  
Substrate Specificity ◽  
Binding Pocket ◽  
Acetyl Coa ◽  
Rational Mutagenesis

scholarly journals DNA tumor virus oncoproteins and retinoblastoma gene mutations share the ability to relieve the cell's requirement for cyclin D1 function in G1.

1994 ◽  
Vol 125 (3) ◽  
pp. 625-638 ◽  
Author(s):  
J Lukas ◽  
H Müller ◽  
J Bartkova ◽  
D Spitkovsky ◽  
A A Kjerulff ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Complex Formation ◽  
Cyclin D1 ◽  
Cell Lines ◽  
T Antigen ◽  
Regulatory Function ◽  
Retinoblastoma Gene ◽  
Checkpoint Control ◽  
Wild Type ◽  
In Cells

The retinoblastoma gene product (pRB) participates in the regulation of the cell division cycle through complex formation with numerous cellular regulatory proteins including the potentially oncogenic cyclin D1. Extending the current view of the emerging functional interplay between pRB and D-type cyclins, we now report that cyclin D1 expression is positively regulated by pRB. Cyclin D1 mRNA and protein is specifically downregulated in cells expressing SV40 large T antigen, adenovirus E1A, and papillomavirus E7/E6 oncogene products and this effect requires intact RB-binding, CR2 domain of E1A. Exceptionally low expression of cyclin D1 is also seen in genetically RB-deficient cell lines, in which ectopically expressed wild-type pRB results in specific induction of this G1 cyclin. At the functional level, antibody-mediated cyclin D1 knockout experiments demonstrate that the cyclin D1 protein, normally required for G1 progression, is dispensable for passage through the cell cycle in cell lines whose pRB is inactivated through complex formation with T antigen, E1A, or E7 oncoproteins as well as in cells which have suffered loss-of-function mutations of the RB gene. The requirement for cyclin D1 function is not regained upon experimental elevation of cyclin D1 expression in cells with mutant RB, while reintroduction of wild-type RB into RB-deficient cells leads to restoration of the cyclin D1 checkpoint. These results strongly suggest that pRB serves as a major target of cyclin D1 whose cell cycle regulatory function becomes dispensable in cells lacking functional RB. Based on available data including this study, we propose a model for an autoregulatory feedback loop mechanism that regulates both the expression of the cyclin D1 gene and the activity of pRB, thereby contributing to a G1 phase checkpoint control in cycling mammalian cells.

Synthesis of Some Novel Benzimidazole Derivatives as Anticancer Agent, and Evaluation for CDK2 Inhibition Activity

2021 ◽  
Vol 17 ◽  
Author(s):  
Rania Helmy Abd El-Hameed ◽  
Samar Said Fatahala ◽  
Amira Ibrahim Sayed
Keyword(s):  
Cell Lines ◽  
Docking Study ◽  
Binding Pocket ◽  
Kinase Assay ◽  
Benzimidazole Derivatives ◽  
Pharmacological Activities ◽  
Anticancer Compounds ◽  
Anti Cancer ◽  
Hct 116

Background: Thiobezimidazoles reveal various pharmacological activities due to similarities with many natural and synthetic molecules, they can easily interact with biomolecules of living systems. Objective: A series of substituted 2-thiobezimidazoles has been synthesized .Twelve final compounds were screened for in vitro anti-cancer activities against sixty different cell-lines. Methods: The spectral data of the synthesized compounds were characterized. Docking study for active anticancer compounds and CDK2/CyclinA2 Kinase assay against standard reference; Imatinib were performed. Results: Two compounds (3c&3l) from the examined series revealed effective antitumor activity in vitro against two-cancer cell lines (Colon Cancer (HCT-116) and Renal Cancer (TK-10). The docking study of synthesized molecules discovered a requisite binding pose in CDK-ATP binding pocket. 3c &3l were promoted in the CDK2/CyclinA2 Kinase assay against standard reference Imatinib. Conclusion: Against all tested compounds ; two compounds 3c &3l were found active against two types of cell-lines.

scholarly journals Creation of Cybrid Cultures Containing mtDNA Mutations m.12315G>A and m.1555G>A, Associated with Atherosclerosis

Biomolecules ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 499 ◽  
Author(s):  
Margarita A. Sazonova ◽  
Vasily V. Sinyov ◽  
Anastasia I. Ryzhkova ◽  
Marina D. Sazonova ◽  
Zukhra B. Khasanova ◽  
...  
Keyword(s):  
Gene Therapy ◽  
Drug Therapy ◽  
Mitochondrial Genome ◽  
Cell Lines ◽  
Threshold Value ◽  
Mtdna Mutation ◽  
Single Nucleotide ◽  
Mtdna Mutations ◽  
Cybrid Cell ◽  
In Cells

In the present work, a pilot creation of four cybrid cultures with high heteroplasmy level was performed using mitochondrial genome mutations m.12315G>A and m.1555G>A. According to data of our preliminary studies, the threshold heteroplasmy level of mutation m.12315G>A is associated with atherosclerosis. At the same time, for a mutation m.1555G>A, such a heteroplasmy level is associated with the absence of atherosclerosis. Cybrid cultures were created by fusion of rho0-cells and mitochondria from platelets with a high heteroplasmy level of the investigated mutations. To create rho0-cells, THP-1 culture of monocytic origin was taken. According to the results of the study, two cybrid cell lines containing mutation m.12315G>A with the heteroplasmy level above the threshold value (25% and 44%, respectively) were obtained. In addition, two cybrid cell lines containing mutation m.1555G>A with a high heteroplasmy level (24%) were obtained. Cybrid cultures with mtDNA mutation m.12315G>A can be used to model both the occurrence and development of atherosclerosis in cells and the titration of drug therapy for patients with atherosclerosis. With the help of cybrid cultures containing single nucleotide replacement of mitochondrial genome m.1555G>A, it is possible to develop approaches to the gene therapy of atherosclerosis.

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