{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,7]],"date-time":"2026-04-07T05:47:12Z","timestamp":1775540832095,"version":"3.50.1"},"reference-count":29,"publisher":"Wiley","issue":"1","license":[{"start":{"date-parts":[[2005,3,3]],"date-time":"2005-03-03T00:00:00Z","timestamp":1109808000000},"content-version":"vor","delay-in-days":7458,"URL":"http:\/\/onlinelibrary.wiley.com\/termsAndConditions#vor"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["European Journal of Biochemistry"],"published-print":{"date-parts":[[1984,10]]},"abstract":"<jats:p>Calf thymus DNA topoisomerase I, which belongs to the eukaryotic type I topoisomerases, is in a typical preparation purified as a set of five major polypeptides with <jats:italic>M<\/jats:italic><jats:sub>r<\/jats:sub> between 70000 and 100000. At least four of these proteins have binding affinity for DNA as was shown by incubating them with radioactive single\u2010stranded DNA after separation in dodecylsulfate polyacrylamide gels and blotting onto nitrocellulose filters. That these polypeptides have DNA relaxing activity was directly demonstrated with protein extracted from single bands of dodecylsulfate\/polyacrylamide gels. We consider the 100000\u2013<jats:italic>M<\/jats:italic><jats:sub>r<\/jats:sub> protein to be the native enzyme. The smaller components are catalytically active fragments of the native topoisomerase most probably arising from limited proteolysis either within the nucleus or during the purification of the enzyme. In two\u2010dimensional non\u2010equilibrium pH\u2010gradient electrophoresis gels the topoisomerase size variants exhibit apparent pI values between 8.1 and 8.3, with small but distinct differences between the components. The calf thymus topoisomerase I, upon binding to phage fd\u2010 DNA, protects a stretch of 15\u201325 nucleotides againt digestion with DNase I.<\/jats:p>","DOI":"10.1111\/j.1432-1033.1984.tb08440.x","type":"journal-article","created":{"date-parts":[[2005,3,3]],"date-time":"2005-03-03T23:15:18Z","timestamp":1109891718000},"page":"127-134","source":"Crossref","is-referenced-by-count":54,"title":["Characterisation of size variants of type I DNA topoisomerase isolated from calf thymus"],"prefix":"10.1111","volume":"144","author":[{"given":"Bertram","family":"SCHMITT","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Ursula","family":"BUHRE","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Hans\u2010Peter","family":"VOSBERG","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"311","published-online":{"date-parts":[[2005,3,3]]},"reference":[{"key":"e_1_2_3_2_2","doi-asserted-by":"publisher","DOI":"10.1016\/S0092-8674(80)80046-8"},{"key":"e_1_2_3_3_2","doi-asserted-by":"publisher","DOI":"10.1146\/annurev.bi.50.070181.004311"},{"key":"e_1_2_3_4_2","doi-asserted-by":"publisher","DOI":"10.3109\/10409238309102799"},{"key":"e_1_2_3_5_2","unstructured":"Vosberg H.\u2010P.(1984)Curr. Top. Microbiol. Immunol. in the press."},{"key":"e_1_2_3_6_2","unstructured":"Prell B.(1980)PhD Thesis Biology Faculty University of Heidelberg."},{"key":"e_1_2_3_7_2","doi-asserted-by":"publisher","DOI":"10.1111\/j.1432-1033.1980.tb04734.x"},{"key":"e_1_2_3_8_2","doi-asserted-by":"publisher","DOI":"10.1021\/bi00666a014"},{"key":"e_1_2_3_9_2","doi-asserted-by":"publisher","DOI":"10.1073\/pnas.72.7.2550"},{"key":"e_1_2_3_10_2","doi-asserted-by":"publisher","DOI":"10.1016\/0006-291X(76)91167-0"},{"key":"e_1_2_3_11_2","doi-asserted-by":"crossref","first-page":"3654","DOI":"10.1016\/S0021-9258(19)69503-7","volume":"256","author":"Gandini\u2010Attardi D.","year":"1981","journal-title":"J. Biol. Chem."},{"key":"e_1_2_3_12_2","doi-asserted-by":"publisher","DOI":"10.1021\/bi00535a008"},{"key":"e_1_2_3_13_2","doi-asserted-by":"publisher","DOI":"10.1073\/pnas.78.6.3487"},{"key":"e_1_2_3_14_2","doi-asserted-by":"publisher","DOI":"10.1073\/pnas.63.4.1164"},{"key":"e_1_2_3_15_2","doi-asserted-by":"publisher","DOI":"10.1016\/0092-8674(77)90176-3"},{"key":"e_1_2_3_16_2","doi-asserted-by":"publisher","DOI":"10.1073\/pnas.76.9.4350"},{"key":"e_1_2_3_17_2","doi-asserted-by":"publisher","DOI":"10.1093\/nar\/8.1.1"},{"key":"e_1_2_3_18_2","doi-asserted-by":"publisher","DOI":"10.1016\/0003-2697(80)90013-5"},{"key":"e_1_2_3_19_2","doi-asserted-by":"publisher","DOI":"10.1016\/S0076-6879(80)65059-9"},{"key":"e_1_2_3_20_2","doi-asserted-by":"publisher","DOI":"10.1016\/S0006-291X(71)80031-1"},{"key":"e_1_2_3_21_2","doi-asserted-by":"publisher","DOI":"10.1016\/S0021-9258(19)41496-8"},{"key":"e_1_2_3_22_2","doi-asserted-by":"publisher","DOI":"10.1016\/S0021-9258(19)69324-5"},{"key":"e_1_2_3_23_2","doi-asserted-by":"publisher","DOI":"10.1093\/nar\/10.21.6945"},{"key":"e_1_2_3_24_2","doi-asserted-by":"crossref","first-page":"137","DOI":"10.1016\/0076-6879(83)00050-6","volume":"100","author":"Martin S. R.","year":"1983","journal-title":"Methods Enzymol."},{"key":"e_1_2_3_25_2","doi-asserted-by":"publisher","DOI":"10.1093\/nar\/11.9.2779"},{"key":"e_1_2_3_26_2","doi-asserted-by":"publisher","DOI":"10.1021\/bi00277a045"},{"key":"e_1_2_3_27_2","doi-asserted-by":"crossref","first-page":"2022","DOI":"10.1016\/S0021-9258(18)33091-6","volume":"258","author":"Badaracco G.","year":"1983","journal-title":"J. Biol. Chem."},{"key":"e_1_2_3_28_2","doi-asserted-by":"publisher","DOI":"10.1093\/nar\/11.2.461"},{"key":"e_1_2_3_29_2","first-page":"537","volume":"41","author":"Durban E.","year":"1981","journal-title":"Cancer Res."},{"key":"e_1_2_3_30_2","doi-asserted-by":"publisher","DOI":"10.1016\/0006-291X(83)91384-0"}],"container-title":["European Journal of Biochemistry"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/api.wiley.com\/onlinelibrary\/tdm\/v1\/articles\/10.1111%2Fj.1432-1033.1984.tb08440.x","content-type":"unspecified","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/febs.onlinelibrary.wiley.com\/doi\/pdf\/10.1111\/j.1432-1033.1984.tb08440.x","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2023,11,22]],"date-time":"2023-11-22T21:48:00Z","timestamp":1700689680000},"score":1,"resource":{"primary":{"URL":"https:\/\/febs.onlinelibrary.wiley.com\/doi\/10.1111\/j.1432-1033.1984.tb08440.x"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[1984,10]]},"references-count":29,"journal-issue":{"issue":"1","published-print":{"date-parts":[[1984,10]]}},"alternative-id":["10.1111\/j.1432-1033.1984.tb08440.x"],"URL":"https:\/\/doi.org\/10.1111\/j.1432-1033.1984.tb08440.x","archive":["Portico"],"relation":{},"ISSN":["0014-2956","1432-1033"],"issn-type":[{"value":"0014-2956","type":"print"},{"value":"1432-1033","type":"electronic"}],"subject":[],"published":{"date-parts":[[1984,10]]}}}