Effects of nuclear isolation on psoralen affinity for chromatin.
We have tested the effects of nuclear isolation on intercalation of TMP (a psoralen) at specific sequences and in total DNA of cultured human cells. DNA in nuclei photobound about 20% more TMP than in cells and about 10% as much as purified DNA. In contrast, a transcribed ras gene and a randomly selected polymorphic sequence each bound about 20% more TMP than total DNA in cells. However, in nuclei, as in purified DNA, both sequences were just as sensitive as total DNA. Apparently, chromatin in cells exists within diverse TMP-binding environments and some of this diversity was lost upon nuclear isolation.
Inadomi
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Rockefeller University, New York, NY 10021-6399.
Ross
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D002151:Calorimetry; D002458:Cell Fractionation / Q000379:methods; D002460:Cell Line; D002467:Cell Nucleus / Q000378:metabolism* / Q000528:radiation effects / Q000648:ultrastructure; D002843:Chromatin / Q000378:metabolism* / Q000528:radiation effects / Q000648:ultrastructure; D003432:Cross-Linking Reagents; D004273:DNA, Neoplasm / Q000378:metabolism*; D005354:Fibrosarcoma; D011564:Furocoumarins / Q000378:metabolism*; D011905:Genes, ras; D006801:Humans; D007700:Kinetics; D014307:Trioxsalen / Q000378:metabolism*; D014316:Tritium; D014466:Ultraviolet Rays; D001749:Urinary Bladder Neoplasms
D002843:Chromatin; D003432:Cross-Linking Reagents; D004273:DNA, Neoplasm; D011564:Furocoumarins; D014316:Tritium; D014307:Trioxsalen