Topostin, a novel inhibitor of mammalian DNA topoisomerase I from Flexibacter topostinus sp. nov. II. Purification and some properties of topostin |
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| Authors: | Y Ikegami N Takeuchi M Hanada Y Hasegawa K Ishii T Andoh T Sato K Suzuki H Yamaguchi S Miyazaki |
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| Affiliation: | Department of Hygienic Chemistry, Meiji College of Pharmacy, Tokyo, Japan. |
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| Abstract: | We describe the isolation of inhibitors of mammalian DNA topoisomerase I, named topostins, from a culture broth of Flexibacter topostinus sp. nov. and some properties of the inhibitors. Topostins A1, A2 and B were isolated by differential solubility in solvents, adsorption chromatography on silica gel and gel filtration on a Sephadex LH-20 column. Topostins A1, A2 and B had specific activities of 4,700, 16,000 and 22,000 U/mg, respectively. The most active metabolite topostin B comprised two components with MW of 567 and 553 in an equimolar ratio. |
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