"Pyran Copolymers" Inhibition of DNA Topoisomerase I from Human Spleen
Bao-Shu, Tang; Wang, Li-Kei; Xu, Xiao-Li; Bao-Shu, Tang, Department of Biology Yunnan College of Education Kunming, P.R. of China; Wang, Li-Kei, Department of Biochemistry Sun Yat-Sen University of Medical Science Guangzhou, P.R. of China; Xu, Xiao-Li, Department of Biochemistry Sun Yat-Sen University of Medical Science Guangzhou, P.R. of China
Журнал:
Journal of Bioactive and Compatible Polymers
Дата:
1990
Аннотация:
"Pyran copolymers" (DIVEMA, FMA and FMAHA), a category of known synthetic polyanions, were found to be potent inhibitors of purified DNA topoisomerase I from human spleen in vitro. DIVEMA, FMA and FMAHA com pletely inhibit the relaxing activity of the topoisomerase I at concentrations of 0.09, 0.6 and 0.5 μg/ml, respectively. The inhibition is reversible. When the substrate (supercoiled plamid PBR322 DNA) and the enzyme are increased to 2 or 3 fold of the initial amount the inhibition is partly overcome. The inhibi tion is specific; they do not inhibit the uncoupling activity of DNA topoiso merase II at a concentration of 100 μg/ml, nor do they inhibit the digesting ac tivity of DNase I at a concentration of 1000 μg/ml.
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