高温DNA聚合酶I的Klenow片段在乙醇中变性的AFM研究  

Denaturation of Bst DNA Polymerse I Klenow Fragment in Alcohol Observed by AFM

作　　者：陈圣福[1] 徐磊 欧阳振乾 张益 李民乾[1] 洪国藩[1] 

机构地区：[1]中国科学院上海原子核研究所,中国科学院上海生物化学研究所

出　　处：《电子显微学报》1997年第6期703-705,共3页Journal of Chinese Electron Microscopy Society

摘　　要：本文利用原子力显微镜（ＡＦＭ），对高温ＤＮＡ聚合酶Ｉ和普通Ｅ．ｃｏｌｉ的ＤＮＡ聚合酶Ｉ的Ｋｌｅｎｏｗ片段在乙醇中变性的对比研究，发现在两种ＤＮＡ聚合酶中都存在结构较紧密的“核”。通过对吸附在云母上的两种酶进行１—１０个小时的处理发现高温聚合酶大多由３块“核”组成，而普通的ＤＮＡ聚合酶由２块“核”组成。这些“核”可能与蛋白的折叠过程中存在的相对稳定的结构区域有关，这对直观了解蛋白折叠过程有一定意义。Atomic Force Microscopy(AFM) has been used to study the changes of main structure in the denaturating process of Bacillus stearothermophilus T 3468 DNA polymerase I Klenow Fragment( Bet pol I KF) and its homologous protein( Escherichia coli DNA polymerase Klenow Fragment) in alcohol.For comparison,images of Bst pol I KF have also been obtained by tapping mode AFM in air,and its contour looks like a kidney or a pear,which is similar to that of Escherichia coli DNA polymerase I Klenow Fragment obtained by X ray diffraction.After treated by alcohol for 2 hours on mica,main structure of the two kinds of fragments relaxed relatively,and after 10 hours manifested two domains formed by two or three parts,which suggests that there are similar cores which may be relative to folding cores in two kinds of homologous protein in pure alcohol and this method is a useful tool for large monomer protein folding.

关 键 词：AFM 乙醇 蛋白变性 DNA聚合酶I Klenow片断 

分 类 号：Q6－33[生物学—生物物理学] Q559.03