scholarly journals The Effect of Dimethyl Sulfoxide on Supercoiled DNA Relaxation Catalyzed by Type I Topoisomerases

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Bei Lv ◽  
Yunjia Dai ◽  
Ju Liu ◽  
Qiang Zhuge ◽  
Dawei Li
Keyword(s):  
Dimethyl Sulfoxide ◽  
Topoisomerase I ◽  
Inhibitory Effect ◽  
Type I ◽  
Supercoiled Plasmid ◽  
Dna Relaxation ◽  
Reaction Solution ◽  
Type Ia ◽  
Typical Type ◽  
Type I Topoisomerases

The effects of dimethyl sulfoxide (DMSO) on supercoiled plasmid DNA relaxation catalyzed by two typical type I topoisomerases were investigated in our studies. It is shown that DMSO in a low concentration (less than 20%, v/v) can induce a dose-related enhancement of the relaxation efficiency ofEscherichia colitopoisomerase I (type IA). Conversely, obvious inhibitory effect on the activity ofcalf thymustopoisomerase I (type IB) was observed when the same concentration of DMSO is used. In addition, our studies demonstrate that 20% DMSO has an ability to reduce the inhibitory effect on EcTopo I, which was induced by double-stranded oligodeoxyribonucleotides while the same effect cannot be found in the case of CtTopo I. Moreover, our AFM examinations suggested that DMSO can change the conformation of negatively supercoiled plasmid by creating some locally loose regions in DNA molecules. Combining all the lines of evidence, we proposed that DMSO enhanced EcTopo I relaxation activity by (1) increasing the single-stranded DNA regions for the activities of EcTopo I in the early and middle stages of the reaction and (2) preventing the formation of double-stranded DNA-enzyme complex in the later stage, which can elevate the effective concentration of the topoisomerase in the reaction solution.

scholarly journals Inhibition of Escherichia coli DNA topoisomerase I activity by phospholipids

1992 ◽  
Vol 285 (2) ◽  
pp. 503-506 ◽  
Author(s):  
T Mizushima ◽  
S Natori ◽  
K Sekimizu
Keyword(s):  
Escherichia Coli ◽  
Fatty Acids ◽  
Topoisomerase I ◽  
Saturated Fatty Acids ◽  
Egg Yolk ◽  
Inhibitory Effect ◽  
Dna Topoisomerase I ◽  
Dna Topoisomerase ◽  
E Coli ◽  
Dna Relaxation

The DNA relaxation activity of Escherichia coli DNA topoisomerase I in vitro was greatly inhibited by cardiolipin. Inhibition also occurred to some extent with phosphatidylglycerol from egg yolk. Analysis with synthetic phospholipid revealed that phosphatidylglycerol containing unsaturated fatty acids exhibited a strong inhibitory effect, whereas inhibition by phosphatidylglycerol containing saturated fatty acids was weak. Phosphatidylethanolamine showed no inhibitory effect. Chlorpromazine, which interacts with phospholipids, suppressed the inhibitory effect of cardiolipin. Cardiolipin and phosphatidylglycerol with unsaturated fatty acid precipitated topoisomerase I even at low concentrations, whereas phosphatidylglycerol from egg yolk and a synthetic phosphatidylglycerol containing saturated fatty acids precipitated this enzyme only at high concentrations. One-third of the total topoisomerase I in E. coli was found in the membrane fraction. Treatment of E. coli cells with chlorpromazine resulted in relaxation of plasmid DNA. This DNA relaxation was not observed in a topA mutant, suggesting that this relaxation by chlorpromazine in vivo is catalysed by topoisomerase I.

Biological Activity of 1-Aryl-3-phenethylamino-1-propanone Hydrochlorides and 3-Aroyl-4-aryl-1-phenethyl-4-piperidinols on PC-3 Cells and DNA Topoisomerase I Enzyme

2010 ◽  
Vol 65 (11-12) ◽  
pp. 647-652 ◽  
Author(s):  
Ebru Mete ◽  
Halise Inci Gul ◽  
Pakize Canturk ◽  
Zeki Topcu ◽  
Bulbul Pandit ◽  
...  
Keyword(s):  
Biological Activity ◽  
Phenyl Ring ◽  
Topoisomerase I ◽  
Mannich Bases ◽  
Type I ◽  
Average Value ◽  
Cytotoxic Compounds ◽  
Type I Topoisomerases ◽  
Supercoil Relaxation ◽  
Anticonvulsant Activities

1aA number of studies reported Mannich bases to manifest antimicrobial, cytotoxic, anticancer, anti-inflammatory, and anticonvulsant activities. A considerable number of therapeutically important cytotoxic compounds are active on DNA topoisomerases that regulate the DNA topology. In the present study we evaluated the biological activity of mono- Mannich bases, 1-aryl-3-phenethylamino-1-propanone hydrochlorides (- 10a), and semicyclic mono- Mannich bases, 3-aroyl-4-aryl-1-phenethyl-4-piperidinols (1b - 9b), synthesized in our laboratory. We employed androgen-independent human prostate cancer cells (PC-3) to assess the cytotoxicity of the compounds and extended the biological activity evaluation to cover supercoil relaxation assays of mammalian type I topoisomerases. Our results showed that the compounds had cytotoxicity within the 8.2 - 32.1 μM range, while two compounds gave rise to a comparable average value in topo I interference of 42% and 40% for 10a (with a hydroxy substituent on the phenyl ring from mono-Mannich bases) and 5b (with a fluoro substituent on the phenyl ring from the semicyclic mono-Mannich base series, piperidinols), respectively

A comparison of topoisomerase I activity in normal and transformed cells

1986 ◽  
Vol 6 (3) ◽  
pp. 301-307 ◽  
Author(s):  
W. H. Colledge ◽  
M. Edge ◽  
J. G. Foulkes
Keyword(s):  
Tyrosine Phosphorylation ◽  
Tyrosine Kinases ◽  
Topoisomerase I ◽  
Transformed Cells ◽  
Type I ◽  
Experimental Conditions ◽  
Viral Oncogenes ◽  
Type I Topoisomerases

Many viral oncogenes encode protein—yrosine kinase activities. However, important in vivo substrates of these enzymes have yet to be identified. Recently, type I topoisomerases were shown to be in vitro substrates for two tyrosine kinases. Following tyrosine phosphorylation, topoisomerase I activity was reduced 10-fold (Tse-Dinh et al. Nature312:785–786, 1984). To determine whether topoisomerase I activity was modulated by tyrosine phosphorylation in vivo, we have measured topoisomerase I activity in nuclear lysates prepared from both normal fibroblasts and cells transformed by two different viral oncogenes (v-abl, v-src). Under a variety of experimental conditions, we have found no evidence to support the notion that type I topoisomerase activity is modulated by tyrosine phosphorylation in vivo.

scholarly journals PRV UL13 inhibits cGAS–STING-mediated IFN-β production by phosphorylating IRF3

2020 ◽  
Vol 51 (1) ◽  
Author(s):  
Zongyi Bo ◽  
Yurun Miao ◽  
Rui Xi ◽  
Qiuping Zhong ◽  
Chenyi Bao ◽  
...  
Keyword(s):  
Transcriptional Activation ◽  
Pseudorabies Virus ◽  
Nuclear Translocation ◽  
Economic Loss ◽  
Inhibitory Effect ◽  
Poly I:C ◽  
Interferon Response ◽  
Type I ◽  
Creb Binding Protein ◽  
Swine Industry

Abstract Cyclic GMP-AMP (cGAMP) synthase (cGAS) is an intracellular sensor of cytoplasmic viral DNA created during virus infection, which subsequently activates the stimulator of interferon gene (STING)-dependent type I interferon response to eliminate pathogens. In contrast, viruses have developed different strategies to modulate this signalling pathway. Pseudorabies virus (PRV), an alphaherpesvirus, is the causative agent of Aujeszky’s disease (AD), a notable disease that causes substantial economic loss to the swine industry globally. Previous reports have shown that PRV infection induces cGAS-dependent IFN-β production, conversely hydrolysing cGAMP, a second messenger synthesized by cGAS, and attenuates PRV-induced IRF3 activation and IFN-β secretion. However, it is not clear whether PRV open reading frames (ORFs) modulate the cGAS–STING-IRF3 pathway. Here, 50 PRV ORFs were screened, showing that PRV UL13 serine/threonine kinase blocks the cGAS–STING-IRF3-, poly(I:C)- or VSV-mediated transcriptional activation of the IFN-β gene. Importantly, it was discovered that UL13 phosphorylates IRF3, and its kinase activity is indispensable for such an inhibitory effect. Moreover, UL13 does not affect IRF3 dimerization, nuclear translocation or association with CREB-binding protein (CBP) but attenuates the binding of IRF3 to the IRF3-responsive promoter. Consistent with this, it was discovered that UL13 inhibits the expression of multiple interferon-stimulated genes (ISGs) induced by cGAS–STING or poly(I:C). Finally, it was determined that PRV infection can activate IRF3 by recruiting it to the nucleus, and PRVΔUL13 mutants enhance the transactivation level of the IFN-β gene. Taken together, the data from the present study demonstrated that PRV UL13 inhibits cGAS–STING-mediated IFN-β production by phosphorylating IRF3.

scholarly journals Role of Curing Temperature of Poly(Glycerol Sebacate) Substrates on Protein-Cell Interaction and Early Cell Adhesion

Polymers ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 382
Author(s):  
Rubén Martín-Cabezuelo ◽  
José Carlos Rodríguez-Hernández ◽  
Guillermo Vilariño-Feltrer ◽  
Ana Vallés-Lluch
Keyword(s):  
Protein Interactions ◽  
Chemical Properties ◽  
Focal Adhesions ◽  
Collagen Type I ◽  
Inhibitory Effect ◽  
Synthesis Temperature ◽  
Curing Temperature ◽  
Cell Protein ◽  
Preliminary Treatment ◽  
Type I

A novel procedure to obtain smooth, continuous polymeric surfaces from poly(glycerol sebacate) (PGS) has been developed with the spin-coating technique. This method proves useful for separating the effect of the chemistry and morphology of the networks (that can be obtained by varying the synthesis parameters) on cell-protein-substrate interactions from that of structural variables. Solutions of the PGS pre-polymer can be spin-coated, to then be cured. Curing under variable temperatures has been shown to lead to PGS networks with different chemical properties and topographies, conditioning their use as a biomaterial. Particularly, higher synthesis temperatures yield denser networks with fewer polar terminal groups available on the surface. Material-protein interactions were characterised by using extracellular matrix proteins such as fibronectin (Fn) and collagen type I (Col I), to unveil the biological interface profile of PGS substrates. To that end, atomic force microscopy (AFM) images and quantification of protein adsorbed in single, sequential and competitive protein incubations were used. Results reveal that Fn is adsorbed in the form of clusters, while Col I forms a characteristic fibrillar network. Fn has an inhibitory effect when incubated prior to Col I. Human umbilical endothelial cells (HUVECs) were also cultured on PGS surfaces to reveal the effect of synthesis temperature on cell behaviour. To this effect, early focal adhesions (FAs) were analysed using immunofluorescence techniques. In light of the results, 130 °C seems to be the optimal curing temperature since a preliminary treatment with Col I or a Fn:Col I solution facilitates the formation of early focal adhesions and growth of HUVECs.

Characterization of specific insulin-like growth factor (IGF)-I and IGF-II receptors on cultured rabbit articular chondrocyte membranes

1989 ◽  
Vol 120 (2) ◽  
pp. 245-249 ◽  
Author(s):  
J. Jansen ◽  
S. C. van Buul-Offers ◽  
C. M. Hoogerbrugge ◽  
T. L. de Poorter ◽  
M. T. Corvol ◽  
...  
Keyword(s):  
Growth Factor ◽  
Type I ◽  
Insulin Like Growth Factor ◽  
Articular Chondrocyte ◽  
Reducing Conditions ◽  
Receptor Sites ◽  
Igf I ◽  
Typical Type ◽  
Liver Membranes ◽  
Placental Membranes

ABSTRACT The interaction of insulin-like growth factor (IGF)-I and IGF-II with specific type-I and -II receptor sites on rabbit articular chondrocyte membranes was studied. With labelled IGF-I as tracer, half-maximal displacement of the label was obtained with 1·4 ng IGF-I/ml and 22 ng IGF-II/ml. Using IGF-II as labelled peptide, 16 ng unlabelled IGF-II/ml and 200 ng IGF-I/ml were needed to inhibit the binding by 50%. Covalent cross-linking experiments revealed the presence of typical type-I (Mr 130 000 under reducing conditions) and type-II (Mr 260 000) receptor sites. In addition, with 125I-labelled IGF-II a very intense labelled band appeared at Mr > 300 000. This band was not found in mouse liver membranes and human placental membranes. Journal of Endocrinology (1989) 120, 245–249

Phagocytic specificity during sexual development in Dictyostelium discoideum

1986 ◽  
Vol 32 (2) ◽  
pp. 79-82 ◽  
Author(s):  
Keith E. Lewis ◽  
Danton H. O'Day
Keyword(s):  
Dictyostelium Discoideum ◽  
Concanavalin A ◽  
Sexual Development ◽  
Wheat Germ ◽  
Giant Cells ◽  
Inhibitory Effect ◽  
Sexual Cycle ◽  
Type I ◽  
Further Development ◽  
Type Receptor

During the sexual cycle of Dictyostelium discoideum, zygote giant cells develop and serve as foci for further development by chemoattracting and cannibalizing hundreds of local amoebae. Previous work has shown that the phagocytic process bears similarities to and differences from asexual endocytosis. In the present study, sexual phagocytosis in D. discoideum was found to be species and developmental stage specific. It was inhibited selectively by glucose and concanavalin A. Although a partial, inhibitory effect of mannose on phagocytosis was not statistically significant, alpha-methylmannosamine, like alpha-methyl-glucose, significantly restored the phagocytic competence of giant cells treated with concanavalin A. Other sugars (N-acetyl glucosamine, N-acetylgalactosamine, and galactose) and lectins (wheat germ agglutinin, Ulex europus type I, and Ricinis communis agglutinin type I) had no significant effect on sexual phagocytosis. Together these data indicate that a glucose-type receptor is involved in selective uptake of D. discoideum amoebae by giant cells.

scholarly journals Inhibitory Effect of thePunica granatumFruit Extract on Angiotensin-II Type I Receptor and Thromboxane B2 in Endothelial Cells Induced by Plasma from Preeclamptic Patients

2016 ◽  
Vol 2016 ◽  
pp. 1-6 ◽  
Author(s):  
Widya Kusumawati ◽  
Kusnarman Keman ◽  
Setyawati Soeharto
Keyword(s):  
Endothelial Cells ◽  
Angiotensin Ii ◽  
Vascular Endothelial Cells ◽  
Ethanolic Extract ◽  
Punica Granatum ◽  
Normal Pregnancy ◽  
Inhibitory Effect ◽  
Thromboxane B2 ◽  
High Dose ◽  
Type I

This study aims to evaluate whether thePunica granatumfruit extract modulates the Angiotensin-II Type I receptor (AT1-R) and thromboxane B2 level in endothelial cells induced by plasma from preeclamptic patients. Endothelial cells were obtained from human umbilical vascular endothelial cells. At confluence, endothelial cells were divided into five groups, which included endothelial cells exposed to 2% plasma from normal pregnancy (NP), endothelial cells exposed to 2% plasma from preeclamptic patients (PP), and endothelial cells exposed to PP in the presence of ethanolic extract ofPunica granatum(PP + PG) at the following three doses: 14; 28; and 56 ppm. The expression of AT1-R was observed by immunohistochemistry technique, and thromboxane B2 level was done by immunoassay technique. Plasma from PP significantly increased AT1-R expression and thromboxane B2 levels compared to cells treated by normal pregnancy plasma. The increasing of AT1-R expression significantly (P<0.05) attenuated by high dose treatments ofPunica granatumextract. Moreover, the increasing of thromboxane B2 levels significantly (P<0.05) attenuated by lowest dose treatments ofPunica granatumextract. We further concluded thatPunica granatumfruit protects and inhibits the sensitivity of endothelial cells to plasma from preeclamptic patients due to inhibition of AT1-R expression (56 ppm) and reduced thromboxane B2 levels (14 ppm).

Sign in / Sign up

Export Citation Format

Share Document