金柑DNA结合蛋白的分离及染色质体外组装研究

Separation of Kumquat DNA-Binding Proteins and Chromatin Assembly in Vvitro

为了研究DNA与DNA结合蛋白的相互作用,以及无细胞的染色质体外组装过程,从金柑叶片中提取总DNA,利用微晶纤维素得到DNA-纤维素层析配体,经DNA-纤维素层析分离得到DNA结合蛋白,再将纯化的DNA和DNA结合蛋白在低盐条件下按一定比例混合,并进行电镜观察。结表表明,该混合物产生絮状沉淀,电镜观察发现念珠状的小黑圆点,因此推测DNA和DNA结合蛋白发生互作,可能形成核小体引起染色质体外组装。

In order to study the interaction between DNA and DNA-binding proteins, an acellular system of chromatin assembly in vitro was established. The total DNA of kumquat leaves were extracted, the DNA-cellulose chromatography ligand was obtained with the microcrystalline cellulose, and then DNA-binding proteins were isolated through the DNA- cellulose chromatography. Finally, the purified DNA and DNA-binding proteins were mixed at a certain proportion under low salt conditions and then observed with electron microscopy. The results showed that the mixture produced flocculent precipitates, and beaded little black dots were found out by the electron microscopy. It indicated that DNA and DNA-binding proteins had interactions, which might lead to the formation of nucleosomes and cause chromatin assembly in vitro.