Pretransition and progressive softening of bovine carbonic anhydrase II as probed by single molecule atomic force microscopy
Pretransition and progressive softening of bovine carbonic anhydrase II as probed by single molecule atomic force microscopy
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DOI：
10.1110/ps.041282305
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发表时间：
2005-06-01
期刊：
影响因子：
8
通讯作者：
Ikai, A
中科院分区：
文献类型：
--
作者：
Afrin, R;Alam, MT;Ikai, A
为了开发一种简单的方法来探测表面吸附的蛋白质的物理状态，我们采用原子力显微镜（AFM）的力曲线模式，以提取信息的机械性质的表面固定化牛碳酸酐酶II在天然条件下，并在氯化胍诱导变性的过程中。在轻度至完全变性条件下，探索了个体软化分子群体的逐渐增加。力曲线的接近制度的使用给出了关于在压缩应力下分子的高度和刚度的信息，而曲线的缩回制度的使用给出了关于蛋白质的拉伸特性的信息。结果表明，蛋白质分子在过渡区的开始具有比天然分子稍微更平坦和显着更软化的构象，但仍然没有完全变性，与基于油溶液研究的结果一致。因此，AFM的力曲线模式被证明是足够灵敏的，以提供有关球状蛋白质的单分子的不同物理状态的信息。
To develop a simple method for probing the physical state of surface adsorbed proteins, we adopted the force Curve mode of an atomic force microscope (AFM) to extract information on the mechanical properties of surf ice immobilized bovine carbonic anhydrase II under native conditions and in the course of guanidinium chloride-induced denaturation. A progressive increase in the population of individually softened molecules was probed under mildly to fully denaturing conditions. The use of the approach regime Of force Curves gave information regarding the height and rigidity of the molecule under compressive stress, whereas use of the retracting regime of the curves gave information about the tensile characteristics of the protein. The results showed that protein Molecules at the beginning of the transition region possessed slightly more flattened and significantly more softened conformations compared with that of native molecules, but were still not fully denatured, in agreement with results based Oil Solution Studies. Thus the force curve mode of an AFM was shown to be sensitive enough to provide information concerning the different physical states of single molecules of globular proteins.