Topostin, a novel inhibitor of mammalian DNA topoisomerase I from Flexibacter topostinus sp. nov. II. Purification and some properties of topostin.
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.
Ikegami
Y
Y
Department of Hygienic Chemistry, Meiji College of Pharmacy, Tokyo, Japan.
Takeuchi
N
N
Hanada
M
M
Hasegawa
Y
Y
Ishii
K
K
Andoh
T
T
Sato
T
T
Suzuki
K
K
Yamaguchi
H
H
Miyazaki
S
S
D002846:Chromatography, Affinity; D002850:Chromatography, Gel; D002855:Chromatography, Thin Layer; D003470:Culture Media / Q000032:analysis; D003589:Cytophaga / Q000032:analysis*; D004264:DNA Topoisomerases, Type I / Q000302:isolation & purification / Q000494:pharmacology; D004269:DNA, Bacterial / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000302:isolation & purification*; D008970:Molecular Weight; D009930:Organic Chemicals; D059004:Topoisomerase I Inhibitors
D003470:Culture Media; D004269:DNA, Bacterial; D004791:Enzyme Inhibitors; D009930:Organic Chemicals; D059004:Topoisomerase I Inhibitors; C063442:topostin A1; C063443:topostin A2; C063444:topostin B; D004264:DNA Topoisomerases, Type I