摘要
The effects of monovalent (Na+, K+) and diva- lent (Mg2+, Ca2+, Mn2+) ions on the interaction between DNA and histone are studied using the molecular combing tech- nique. ?-DNA molecules and DNA-histone complexes incu- bated with metal cations (Na+, K+, Mg2+, Ca2+, Mn2+) are stretched on hydrophobic surfaces, and directly observed by fluorescence microscopy. The results indicate that when these cations are added into the DNA solution, the fluorescence intensities of the stained DNA are reduced differently. The monovalent cations (Na+, K+) inhibit binding of histone to DNA. The divalent cations (Mg2+, Ca2+, Mn2+) enhance sig- nificantly the binding of histone to DNA and the binding of the DNA-histone complex to the hydrophobic surface. Mn2+ also induces condensation and aggregation of the DNA- his- tone complex.
The effects of monovalent (Na+, K+) and divalent (Mg2+, Ca2+, Mn2+) ions on the interaction between DNA and histone are studied using the molecular combing technique. X-DNA molecules and DNA-histone complexes incubated with metal cations (Na+, K+, Mg2+, Ca2+, Mn2+) are stretched on hydrophobic surfaces, and directly observed by fluorescence microscopy. The results indicate that when these cations are added into the DNA solution, the fluorescence intensities of the stained DNA are reduced differently. The monovalent cations (Na+, K+) inhibit binding of histone to DNA. The divalent cations (Mg2+, Ca2+, Mn2+) enhance significantly the binding of histone to DNA and the binding of the DNA-histone complex to the hydrophobic surface. Mn2+ also induces condensation and aggregation of the DNA-histone complex.
基金
supported by the National Natural Science Foundation of China(Grant Nos.60025516 and 10334100).
关键词
DNA
组蛋白
金属离子
荧光显微镜法
DNA
histone
molecular combing
metal cation
fluorescence microscopy