γ射线辐照对天然DNA分子构象的影响。

Effect of gamma-irradiation on the conformation of the native DNA molecule.

作者信息

Frisman E, Zarubina O

机构信息

Physical Institute of St. Petersburg University, Russian Federation.

出版信息

Biophys Chem. 1993 Feb;46(1):37-46. doi: 10.1016/0301-4622(93)87005-h.

DOI:10.1016/0301-4622(93)87005-h

PMID:8443334

Abstract

Extensive investigation of gamma-irradiated DNA solutions with the application of several informative physical methods suggested that at doses of 10-30 Gy the observed change in the size of the DNA molecule is due to a decrease in long-range interactions in the macromolecule. The comparison of the results of investigations of non-irradiated and irradiated DNA and its complexes with low molecular weight ligands over a wide range of ionic strengths showed that these interactions are electrostatic in nature and are due to a decrease in the charge density on the DNA molecule when its solutions are irradiated. In the irradiation dose range discussed here, the persistent length of the DNA molecule determined by short-range interactions in the chain does not undergo pronounced changes. It is shown that the free ligand in the irradiated solution can protect the DNA molecule against radiation damage. In contrast, the ligand bonded by intercalation does not exhibit this ability.

摘要

运用多种信息丰富的物理方法对γ射线辐照的DNA溶液进行广泛研究表明，在10 - 30 Gy的剂量下，观察到的DNA分子大小变化是由于大分子中长程相互作用的减少。在广泛的离子强度范围内，对未辐照和辐照的DNA及其与低分子量配体的复合物的研究结果比较表明，这些相互作用本质上是静电作用，并且是由于DNA溶液辐照时DNA分子上电荷密度的降低所致。在此讨论的辐照剂量范围内，由链中短程相互作用决定的DNA分子的持久长度没有明显变化。结果表明，辐照溶液中的游离配体可以保护DNA分子免受辐射损伤。相比之下，通过嵌入结合的配体则不具备这种能力。