{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,10]],"date-time":"2026-06-10T16:28:43Z","timestamp":1781108923751,"version":"3.54.1"},"reference-count":0,"publisher":"National Academy of Sciences","issue":"3","content-domain":{"domain":["www.pnas.org"],"crossmark-restriction":true},"short-container-title":["Proc. Natl. Acad. Sci. U.S.A."],"published-print":{"date-parts":[[1982,2]]},"abstract":"<jats:p>\n                    Snake venom phosphodiesterase or endonuclease S1 digestion of neocarzinostatin chromophore-treated DNA, labeled in its thymidine residues, liberates an unusual labeled nucleoside from the 5\u2032 end of a drug-induced break. This substance, isolated by reverse-phase HPLC, possesses carbons from both the thymine and the deoxyribose moieties of thymidine in the DNA but, unlike thymidine, is readily degraded at pH 12 to thymine and a sugar fragment. The altered nucleoside was shown to contain a carbonyl group by its reduction with NaBH\n                    <jats:sub>4<\/jats:sub>\n                    to form a substance that has the chromatographic properties of thymidine and by its reaction with various hydrazines to form the respective hydrazone derivatives; the carbonyl exists as the 5\u2032 aldehyde as shown by its mild chemical oxidation to the carboxylic acid with simultaneous loss of the 5\u2032\n                    <jats:sup>3<\/jats:sup>\n                    H. Mass spectral analysis showed a fragmentation pattern compatible with the structure thymidine-5\u2032-aldehyde. These data indicate that the nonprotein chromophore of neocarzinostatin, in the presence of a reducing substance (2-mercaptoethanol) and molecular oxygen, selectively oxidizes the 5\u2032 carbon of nucleosides in DNA to the aldehyde, resulting in a strand break and a DNA fragment bearing nucleoside-5\u2032-aldehyde at its 5\u2032 end.\n                  <\/jats:p>","DOI":"10.1073\/pnas.79.3.744","type":"journal-article","created":{"date-parts":[[2006,5,31]],"date-time":"2006-05-31T03:16:44Z","timestamp":1149045404000},"page":"744-748","update-policy":"https:\/\/doi.org\/10.1073\/pnas.cm10313","source":"Crossref","is-referenced-by-count":33,"title":["Identification of thymidine-5\u2032-aldehyde at DNA strand breaks induced by neocarzinostatin chromophore"],"prefix":"10.1073","volume":"79","author":[{"given":"Lizzy S.","family":"Kappen","sequence":"first","affiliation":[{"name":"Department of Pharmacology, Harvard Medical School, Boston, Massachusetts 02115"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Irving H.","family":"Goldberg","sequence":"additional","affiliation":[{"name":"Department of Pharmacology, Harvard Medical School, Boston, Massachusetts 02115"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jerrold M.","family":"Liesch","sequence":"additional","affiliation":[{"name":"Merck, Sharp and Dohme Research Laboratories, Rahway, New Jersey 07065"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"341","published-online":{"date-parts":[[1982,2]]},"container-title":["Proceedings of the National Academy of Sciences"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/pnas.org\/doi\/pdf\/10.1073\/pnas.79.3.744","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2022,4,13]],"date-time":"2022-04-13T11:46:38Z","timestamp":1649850398000},"score":1,"resource":{"primary":{"URL":"https:\/\/pnas.org\/doi\/full\/10.1073\/pnas.79.3.744"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[1982,2]]},"references-count":0,"journal-issue":{"issue":"3","published-print":{"date-parts":[[1982,2]]}},"alternative-id":["10.1073\/pnas.79.3.744"],"URL":"https:\/\/doi.org\/10.1073\/pnas.79.3.744","relation":{},"ISSN":["0027-8424","1091-6490"],"issn-type":[{"value":"0027-8424","type":"print"},{"value":"1091-6490","type":"electronic"}],"subject":[],"published":{"date-parts":[[1982,2]]},"assertion":[{"value":"1982-02-01","order":2,"name":"published","label":"Published","group":{"name":"publication_history","label":"Publication History"}}]}}