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Medicine and Health Sciences Commons

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Medical Microbiology

Florida International University

Department of Chemistry and Biochemistry

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Full-Text Articles in Medicine and Health Sciences

Identification Of Anziaic Acid, A Lichen Depside From Hypotrachyna Sp., As A New Topoisomerase Poison Inhibitor, Bokun Cheng, Shugeng Cao, Victor Vasquez, Thirunavukkarasu Annamalai, Giselle Tamayo-Castillo, Yuk-Ching Tse-Dinh Apr 2013

Identification Of Anziaic Acid, A Lichen Depside From Hypotrachyna Sp., As A New Topoisomerase Poison Inhibitor, Bokun Cheng, Shugeng Cao, Victor Vasquez, Thirunavukkarasu Annamalai, Giselle Tamayo-Castillo, Yuk-Ching Tse-Dinh

Department of Chemistry and Biochemistry

Topoisomerase inhibitors are effective for antibacterial and anticancer therapy because they can lead to the accumulation of the intermediate DNA cleavage complex formed by the topoisomerase enzymes, which trigger cell death. Here we report the application of a novel enzyme-based high-throughput screening assay to identify natural product extracts that can lead to increased accumulation of the DNA cleavage complex formed by recombinant Yersinia pestistopoisomerase I as part of a larger effort to identify new antibacterial compounds. Further characterization and fractionation of the screening positives from the primary assay led to the discovery of a depside, anziaic acid, from the lichen …


Instability Of Ctg Repeats Is Governed By The Position Of A Dna Base Lesion Through Base Excision Repair, Yanhao Lai, Meng Xu, Zunzhen Zhang, Yuan Liu Feb 2013

Instability Of Ctg Repeats Is Governed By The Position Of A Dna Base Lesion Through Base Excision Repair, Yanhao Lai, Meng Xu, Zunzhen Zhang, Yuan Liu

Department of Chemistry and Biochemistry

Trinucleotide repeat (TNR) expansions and deletions are associated with human neurodegeneration and cancer. However, their underlying mechanisms remain to be elucidated. Recent studies have demonstrated that CAG repeat expansions can be initiated by oxidative DNA base damage and fulfilled by base excision repair (BER), suggesting active roles for oxidative DNA damage and BER in TNR instability. Here, we provide the first evidence that oxidative DNA damage can induce CTG repeat deletions along with limited expansions in human cells. Biochemical characterization of BER in the context of (CTG)20 repeats further revealed that repeat instability correlated with the position of a base …