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Topoisomerase II Drug Screening and Xanthocidin

Topoisomerase II Drug Screening and Xanthocidin

These researchers have cleverly identified a way to synthesize derivatives of an unstable compound group with potential as Topoisomerase IIa inhibitors. Topo II and Drug Screening kits for the analysis of enzyme reactivity and DNA cleavage were provided by TopoGEN. Article Source: The Pharmaceutical Society of Japan Biological and Pharmaceutical Bulletin Xanthocidin Derivatives as Topoisomerase IIα Enzymatic Inhibitors Abstract Few studies have examined xanthocidin, a biotic isolated from Streptomyces xanthocidicus in 1966, because its supply is limited. Based on its…

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Study Reveals Novel Approach to Reducing Toxic Effects of Amonafide

Study Reveals Novel Approach to Reducing Toxic Effects of Amonafide

This study which originally was published in Bioorganic and Medicinal Chemistry in November 2013, describes a novel approach to reducing the toxic side effects of amonafide, a drug used in the treatment of cancer which is considered a topoisomerase II poison. Article Source: Science Direct Synthesis and study of antiproliferative, antitopoisomerase II, DNA-intercalating and DNA-damaging activities of arylnaphthalimides Abstract A series of arylnaphthalimides were designed and synthesized to overcome the dose-limiting cytotoxicity of N-acetylated metabolites arising from amonafide, the prototypical…

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Topo I and Cobalt Complex

Topo I and Cobalt Complex

Revealing new paper on metallo-inhibitors. Article Source: Science Direct Synthesis and structure elucidation of a cobalt(II) complex as topoisomerase I inhibitor: In vitro DNA binding, nuclease and RBC hemolysis Abstract Metal-based cancer chemotherapeutic agent of the type Co(II) complex [Co(mpca)2]·H2O (1), where, Hmpca = 9-methyl-[1,10]phenanthroline-2-carboxylic acid was synthesized and characterized by various spectroscopic and analytical techniques and further authenticated by single crystal X-ray diffraction methods. In vitro DNA binding studies of complex 1 with CT DNA was carried out by…

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Supercoiling DNA with Reverse Gyrase

Supercoiling DNA with Reverse Gyrase

A new reverse gyrase from Pyrobaculum species has been identified with some novel properties. It combines helicase with topoisomerase domains. Very interesting from an evolutionary perspective. Article Source: The Journal of Biological Chemistry The reverse gyrase form Pyrobaculum calidifontis, a novel extremely thermophilic DNA topoisomerase endowed with DNA unwinding and annealing activities Abstract Reverse gyrase is a DNA topoisomerase specific of hyperthermophilic bacteria and archaea. It catalyses the peculiar ATP-dependent DNA positive supercoiling reaction and might be involved in the…

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Topoisomerase II Targeting and Resveratrol

Topoisomerase II Targeting and Resveratrol

In this paper the authors use a decatenation assay to identify some new topoisomerase II inhibitors from resveratrol. kDNA substrate was provided by TopoGEN. Article Source: Journal of Agricultural and Food Chemistry Topoisomerase II-Targeting Properties of a Grapevine-Shoot Extract and Resveratrol Oligomers Abstract Grapevine-shoot extracts (GSE), containing trans-resveratrol and resveratrol oligomers, are commercially available as food supplements. Considering the topoisomerase-targeting properties of trans-resveratrol, the question of whether GSE affect these enzymes, thereby potentially causing DNA damage, was addressed. In a…

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Topoisomerase Inhibition and Torsional Stress

Topoisomerase Inhibition and Torsional Stress

Topology is critical in allowing chromatin to function in a normal manner. DNA templating is clearly impacted when enzymes that relieve strain are blocked in a chromatin context. Specifically, inhibition of topoisomerases leads to rapid accumulation of torsional strain accompanied by changes in Pol II kinetics and destabilization of nucleosomes. Transcription-generated torsional stress destabilizes nucleosomes Article Source: Nature Abstract As RNA polymerase II (Pol II) transcribes a gene, it encounters an array of well-ordered nucleosomes. How it traverses through this…

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Embryogenesis and Topo I: Screening for Cheaters

Embryogenesis and Topo I: Screening for Cheaters

The authors have used a clever genetic screen to identify “Cheater mutations” in genes that confer the ability of cells to behave in a non-cooperative fashion in a tissue context. These cheater cells could for example, outgrow surrounding cells as aberrant clones, and thereby derail a tightly regulated process of differentiation that is pivotal in development. A very nice bioinformatic rendering of the data revealed that an axis of regulatory genes that are under the influence of topoisomerase I and…

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Mutations and Drug Resistance: Topo I and Irinotecan

Mutations and Drug Resistance: Topo I and Irinotecan

Low efficacy of a particular class of anti-cancer agents is discussed in this article. The authors hypothesize that Topoisomerase I mutations cause a resistance to Irinotecan, a commonly used drug for the treatment of colon cancer. Article Source: Molecular Cancer New Topoisomerase I mutations are associated with resistance to camptothecin Abstract Background: Topoisomerase I (TOP1) is a nuclear enzyme that catalyzes the relaxation of supercoiled DNA during DNA replication and transcription. TOP1 is the molecular target of camptothecin and related…

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Findings on the Dissasemblage of Particular Nuclear Subdomain in Tumor Cells

Findings on the Dissasemblage of Particular Nuclear Subdomain in Tumor Cells

The authors discuss the particulars of the perinucluear compartment in DNA and its effects on the DNA integrity of a tumor rich environment. Human Topo I Antibody provided by TopoGEN. Article Source: The Journal of Biological Chemistry The Perinucleolar Compartment Is Directly Associated with DNA Abstract The perinucleolar compartment (PNC) is a nuclear subdomain that is unique to tumor cells, and the percentage of cells in a population containing PNCs (PNC prevalence) indicates the level of malignancy of that population….

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Quantifying Topo Action in E. Coli

Quantifying Topo Action in E. Coli

A new method to quantify endogenous Topoisomerase action in E. coli cells is nicely described in this paper. The technique is based on the In Vivo Link Kit, also known as the ICE bioassay. Article Source: American Society for Microbiology Isolation and Quantitation of Topoisomerase Complexes Accumulated on Escherichia coli Chromosomal DNA Abstract DNA topoisomerases are important targets in anticancer and antibacterial therapy because drugs can initiate cell death by stabilizing the transient covalent topoisomerase-DNA complex. In this study, we…

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