荧光能量转移和偏振研究小牛胸腺DNA与组蛋白在高低离子盐溶液中的离合

本文研究小牛胸腺DNA和组蛋白在体外低、高离子强度盐溶液中的动态缔合与解离。 实验结果是低离子溶液中荧光给体DANsyl-Cl-组蛋白在发射峰位上荧光强度降低,荧光受体吖啶橙-DNA在发射峰位上的荧光强度增高。此两峰位上荧光受体的荧光增量比值是2.7/1(大于1),有能量转移发生,DNA和组蛋白缔合。高离子溶液中两峰位上受体的荧光增量比值降到1.6/1,能量转移减少,DNA和组蛋白解离。 低离子溶液中所得的吖啶橙-DNA的荧光偏振度P值小而高离子溶液中的P值大。说明解离的DNA硷基排列比缔合的DNA硷基排列有序程度强,进一步证明低离子溶液中DNA和组蛋白是缔合的,而高离子溶液中它们是解离的。

STUDY OF ASSOCIATION AND DISSOCIATION OF DNA AND HISTONE OF CALF THYMUS IN LOW AND HIGH IONIC STRENGTH SOLUTION BY FLUORESCENCE ENERGY TRANSFER AND POLARIZATION.

The association and dissociation of DNA and histone in vitro was related to the ionic strength of their solution environment.Their association and dissociation slates can be measured with the fluorescence energy transfer and polarization.In this paper we studied the association and dissociation of DNA and histone of ralf thymus in vitro.It is valuable to reasoning the variation of chromatin structure when the ionic concentration varies in vivo.The result is that the fluorescence strength of fluorescence donor were fallen down and that of fluorescence receptor were increased respectively when they are in low ionic strength solution,but the energy transfer was fallen down when they are in high ionic solution.The P value of DNA was low in low ionic strength solution and high in high ionic strength solution.So we concluded that the DNA and histone were associated in low ionic strength solution and they were dissociated in high ionic strength solution.