New technique for uncoupling the cleavage and religation reactions of eukaryotic topoisomerase I. The mode of action of camptothecin at a specific recognition site. Export

@article{citeulike:2970892, abstract = {A new technique for uncoupling the cleavage and religation half-reactions of topoisomerase I at a specific site has been developed. The technique takes advantage of a suicidal DNA substrate to attain enzyme-mediated cleavage without concomitant religation. Efficient religation can be achieved, subsequently, by addition of an oligonucleotide capable of hybridising to the non-cleaved strand of the suicide DNA substrate. The technique was used to study the effect of different compounds on the half-reactions of topoisomerase I. It was shown that topoisomerase I-mediated cleavage was inhibited by NaCl concentrations higher than 200 mM, while the religation reaction seemed unaffected by concentrations as high as 3 M-NaCl. The divalent cations Mg2+, Ca2+ and Mn2+ were found to enhance the cleavage but not the religation reaction of topoisomerase I, whereas Cu2+ and Zn2+ inhibited both reactions. Furthermore, the effect of the anti-neoplastic agent, camptothecin, on the half-reactions of topoisomerase I was investigated. It was found that the drug did not affect the cleavage reaction of topoisomerase I at the studied site, while the religation reaction of the enzyme was inhibited. Camptothecin was found to stabilise the enzyme-DNA cleavage complex even when the drug was added after complex formation.}, address = {Department of Molecular Biology and Plant Physiology, University of Aarhus, Denmark.}, author = {Svejstrup, J. Q. and Christiansen, K. and Gromova, I. I. and Andersen, A. H. and Westergaard, O.}, citeulike-article-id = {2970892}, citeulike-linkout-0 = {http://view.ncbi.nlm.nih.gov/pubmed/1660929}, citeulike-linkout-1 = {http://www.hubmed.org/display.cgi?uids=1660929}, day = {5}, issn = {0022-2836}, journal = {Journal of molecular biology}, keywords = {cepa}, month = {December}, number = {3}, pages = {669--678}, posted-at = {2009-01-27 14:57:16}, priority = {2}, title = {New technique for uncoupling the cleavage and religation reactions of eukaryotic topoisomerase I. The mode of action of camptothecin at a specific recognition site.}, url = {http://view.ncbi.nlm.nih.gov/pubmed/1660929}, volume = {222}, year = {1991} }

TY - JOUR ID - citeulike:2970892 L3 - citeulike-article-id:2970892 N2 - A new technique for uncoupling the cleavage and religation half-reactions of topoisomerase I at a specific site has been developed. The technique takes advantage of a suicidal DNA substrate to attain enzyme-mediated cleavage without concomitant religation. Efficient religation can be achieved, subsequently, by addition of an oligonucleotide capable of hybridising to the non-cleaved strand of the suicide DNA substrate. The technique was used to study the effect of different compounds on the half-reactions of topoisomerase I. It was shown that topoisomerase I-mediated cleavage was inhibited by NaCl concentrations higher than 200 mM, while the religation reaction seemed unaffected by concentrations as high as 3 M-NaCl. The divalent cations Mg2+, Ca2+ and Mn2+ were found to enhance the cleavage but not the religation reaction of topoisomerase I, whereas Cu2+ and Zn2+ inhibited both reactions. Furthermore, the effect of the anti-neoplastic agent, camptothecin, on the half-reactions of topoisomerase I was investigated. It was found that the drug did not affect the cleavage reaction of topoisomerase I at the studied site, while the religation reaction of the enzyme was inhibited. Camptothecin was found to stabilise the enzyme-DNA cleavage complex even when the drug was added after complex formation. IS - 3 JF - Journal of molecular biology SN - 0022-2836 AD - Department of Molecular Biology and Plant Physiology, University of Aarhus, Denmark. EP - 678 TI - New technique for uncoupling the cleavage and religation reactions of eukaryotic topoisomerase I. The mode of action of camptothecin at a specific recognition site. VL - 222 SP - 669 KW - cepa AU - Svejstrup, JQ AU - Christiansen, K AU - Gromova, II AU - Andersen, AH AU - Westergaard, O PY - 1991/12/05/ UR - http://view.ncbi.nlm.nih.gov/pubmed/1660929 ER -