{"title":"适度加热前后人成纤维细胞和HeLa系肿瘤细胞DNA沉降率的比较研究。","authors":"M M Vilenchik, A N Khokhlov","doi":"","DOIUrl":null,"url":null,"abstract":"<p><p>Changes in DNA after heating of human cells at 43.5 and 44 degrees C were found for the first time by means of sedimentation in an alkaline sucrose gradient. These changes are probably mainly determined by three processes: the appearance in DNA of alkali-labile bonds, the formation of stable DNA--protein complexes, and changes in the superstructure of the DNA, in particular partial unfolding of the nucleosomes. The existence of a mechanism for nonexcision repair of thermal lesions in DNA by an enzyme (\"repurinase\") catalyzing the formation of a glycoside bond between the base of a purine precursor of DNA and the deoxyribose residue of an apurine component is suggested.</p>","PeriodicalId":9166,"journal":{"name":"Biology bulletin of the Academy of Sciences of the USSR","volume":"7 1","pages":"33-9"},"PeriodicalIF":0.0000,"publicationDate":"1980-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Comparative investigation of rate of sedimentation of DNA from human fibroblasts and tumor cells of HeLa line before and after moderate heating.\",\"authors\":\"M M Vilenchik, A N Khokhlov\",\"doi\":\"\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<p><p>Changes in DNA after heating of human cells at 43.5 and 44 degrees C were found for the first time by means of sedimentation in an alkaline sucrose gradient. These changes are probably mainly determined by three processes: the appearance in DNA of alkali-labile bonds, the formation of stable DNA--protein complexes, and changes in the superstructure of the DNA, in particular partial unfolding of the nucleosomes. The existence of a mechanism for nonexcision repair of thermal lesions in DNA by an enzyme (\\\"repurinase\\\") catalyzing the formation of a glycoside bond between the base of a purine precursor of DNA and the deoxyribose residue of an apurine component is suggested.</p>\",\"PeriodicalId\":9166,\"journal\":{\"name\":\"Biology bulletin of the Academy of Sciences of the USSR\",\"volume\":\"7 1\",\"pages\":\"33-9\"},\"PeriodicalIF\":0.0000,\"publicationDate\":\"1980-01-01\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Biology bulletin of the Academy of Sciences of the USSR\",\"FirstCategoryId\":\"1085\",\"ListUrlMain\":\"\",\"RegionNum\":0,\"RegionCategory\":null,\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"\",\"JCRName\":\"\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Biology bulletin of the Academy of Sciences of the USSR","FirstCategoryId":"1085","ListUrlMain":"","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
Comparative investigation of rate of sedimentation of DNA from human fibroblasts and tumor cells of HeLa line before and after moderate heating.
Changes in DNA after heating of human cells at 43.5 and 44 degrees C were found for the first time by means of sedimentation in an alkaline sucrose gradient. These changes are probably mainly determined by three processes: the appearance in DNA of alkali-labile bonds, the formation of stable DNA--protein complexes, and changes in the superstructure of the DNA, in particular partial unfolding of the nucleosomes. The existence of a mechanism for nonexcision repair of thermal lesions in DNA by an enzyme ("repurinase") catalyzing the formation of a glycoside bond between the base of a purine precursor of DNA and the deoxyribose residue of an apurine component is suggested.