Iurgaĭtis A P, Lazurkin Iu S, Bannikov Iu A
Mol Biol (Mosk). 1979 May-Jun;13(3):531-42.
The effect of single- and double-stranded breaks in DNA phage T2, on the melting temperature of this DNA in the 0,05 M SSC solution, was investigated. The number of cleavages per 1000 nucleotide pairs varied in the range of 0 to 10. It is shown that single- and double-stranded breaks affect the melting temperature with approximately (within 20%) the same efficiency. The relationship between the melting temperature shift (delta Tm) and the number of cleavages is non-linear. The magnitude of the effect is characterized by delta Tm of 2 +/- 0.4 degrees C for the average inter-cleavage distance of 200 base pairs. It is shown that the observed melting curves are non-equilibrium ones, which is probably due to the fact that the effect of cleavages on the melting temperature is largely results from the complete and practically irreversible separation of strands.
研究了DNA噬菌体T2中的单链和双链断裂对该DNA在0.05M SSC溶液中的解链温度的影响。每1000个核苷酸对的切割数在0到10的范围内变化。结果表明，单链和双链断裂对解链温度的影响效率大致相同（在20%以内）。解链温度变化（ΔTm）与切割数之间的关系是非线性的。对于平均切割间距为200个碱基对的情况，效应大小的特征是ΔTm为2±0.4℃。结果表明，观察到的解链曲线是非平衡曲线，这可能是由于切割对解链温度的影响很大程度上源于链的完全且几乎不可逆的分离。
