铂（II）配合物在λ噬菌体DNA中产生的失活损伤的性质。

The nature of inactivating lesions produced by platinum(II) complexes in phage lambda DNA.

作者信息

Filipski J, Kohn K W, Bonner W M

出版信息

Chem Biol Interact. 1980 Nov;32(3):321-30. doi: 10.1016/0009-2797(80)90099-x.

Abstract

Lambda DNA loses transfectivity and acquires interstrand cross-links after treatment with either trans-Pt(II) or cis-Pt(II). With trans-Pt(II) there is close to an equivalence between the fraction of lambda DNA cross-linked and the fraction inactivated. In contrast, with cis-Pt(II) there are approx. 5 inactivating lesions for each lambda DNA interstrand cross-link. These results suggested that trans-PT(II) does not introduce intrastrand inactivating lesions into lambda DNA while cis-Pt(II) does so. To verify this conclusion, the cross-linked and uncross-linked fractions of lambda DNA treated with trans-PT(II) or cis-Pt(II) were separated on alkaline sucrose gradients. After trans-Pt(II) treatment, the uncross-linked fraction of lambda DNA was transfective when renaturated. However after cis-Pt(II) treatment the uncross-linked fraction of lambda DNA was not transfective when renatured. Thiourea treatment restored transfectivity to all inactivated fractions, showing that these lesions are reversible. We conclude that trans-Pt(II) inactivates lambda DNA primarily by introducing interstrand cross-links but that cis-Pt(II), although it also introduces interstrand cross-links, inactivates lambda DNA primarily by introducing intrastrand lesions.

摘要

用反式铂（II）或顺式铂（II）处理后，λ噬菌体DNA失去转染性并形成链间交联。对于反式铂（II），λ噬菌体DNA交联部分与失活部分接近等效。相比之下，对于顺式铂（II），每个λ噬菌体DNA链间交联大约有5个失活损伤。这些结果表明，反式铂（II）不会在λ噬菌体DNA中引入链内失活损伤，而顺式铂（II）会。为了验证这一结论，用反式铂（II）或顺式铂（II）处理的λ噬菌体DNA的交联部分和未交联部分在碱性蔗糖梯度上进行分离。反式铂（II）处理后，λ噬菌体DNA的未交联部分复性时具有转染性。然而，顺式铂（II）处理后，λ噬菌体DNA的未交联部分复性时没有转染性。硫脲处理使所有失活部分恢复转染性，表明这些损伤是可逆的。我们得出结论，反式铂（II）主要通过引入链间交联使λ噬菌体DNA失活，而顺式铂（II）虽然也引入链间交联，但主要通过引入链内损伤使λ噬菌体DNA失活。