title: S1 nuclease sensitivity to cis- and trans-diamminedichloroplatinum(II) modified DNAS: influence of (G+C) content and nucleotide sequence.
abstract: The sensitivity of S1 nuclease to cis- and trans-(NH3)2PtCl2 modified DNAs is examined as a function of the level of cis- and trans-(NH3)2PtCl2 bound, the % (G+C) content in DNA from different sources and the sequence dependence in poly(dG).poly(dC) and poly(dG-dC).poly(dG-dC). The extent of DNA digested increases with increasing levels of either isomer and is inversely influenced by the % (G+C) content of the DNA. However, the difference in the extent of digestion between the cis-and trans-(NH3)2PtCl2 modified DNAs at equivalent levels of bound isomer follows the order, calf-thymus greater than M. lysodeikticus greater than poly(dG-dC).poly(dG-dC). While there is virtually no difference in the digestion profiles for poly(dG-dC).poly(dG-dC) modified with the two isomers, there is a striking difference in the extent of digestion between cis- and trans-(NH3)2PtCl2 modified poly(dG).poly(dC). These results are discussed in light of the possible modes of binding for cis-(NH3)2PtCl2, previously reported findings on modified DNA and possible implications for modifications in cellular chromatin.
mesh_terms: D000818:Animals; D001483:Base Sequence; D002417:Cattle; D002945:Cisplatin / Q000494:pharmacology*; D003596:Cytosine; D004247:DNA; D004720:Endonucleases / Q000378:metabolism*; D006147:Guanine; D007536:Isomerism; D007700:Kinetics; D011089:Polydeoxyribonucleotides; D015719:Single-Strand Specific DNA and RNA Endonucleases; D013950:Thymus Gland
chemical_list: D011089:Polydeoxyribonucleotides; C034697:transplatin; C019530:poly(dC-dG); D006147:Guanine; D003596:Cytosine; D004247:DNA; D004720:Endonucleases; D015719:Single-Strand Specific DNA and RNA Endonucleases; D002945:Cisplatin