Biomacromolecules evolve and function inside the cell under crowded conditions. The effect of macromolecular crowding and confinement on nature and interactions of biomacromolecules cannot be ruled out. This study demonstrates the effect of volume exclusion due to macromolecular crowding on refolding rate of Gn-HCl induced unfolded hemoglobin. The in vivo like crowding milieu was created using dextran 70. Unfolding of Hb was followed by the absorbance at 280 nm and intrinsic fluorescence intensity along with a bathochromic shift that shows the destabilization of Hb in the presence of the denaturing agent. This was supported by a decrease in soret absorbance, increased hydrodynamic radii and loss in secondary structure, evidenced from dynamic light scattering and circular dichroism experiments respectively. Refolding process of Hb was followed by an increase in soret absorbance, decrease in intrinsic fluorescence intensity with a hypsochromic shift, decreased hydrodynamic radii and gain in secondary structural content. The results revealed that the effect of confinement and volume exclusion is insignificant on the process of Hb refolding.

中文翻译：

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大分子限制下血红蛋白的再折叠：模拟体内体积排除。

在拥挤的条件下，生物大分子在细胞内进化并发挥作用。不能排除大分子拥挤和限制对生物大分子的性质和相互作用的影响。该研究证明了由于大分子拥挤导致的体积排阻对 Gn-HCl 诱导的未折叠血红蛋白的再折叠率的影响。使用 dextran 70 创建了体内类似拥挤的环境。 Hb 展开后是 280 nm 的吸光度和固有荧光强度以及显示在变性剂存在下 Hb 不稳定的红移。这得到了 soret 吸光度降低、流体动力学半径增加和二级结构损失的支持，分别由动态光散射和圆二色性实验证明。Hb 的重折叠过程之后是 soret 吸光度的增加、内在荧光强度的降低以及低色移、流体动力学半径的降低和二级结构含量的增加。结果表明，限制和体积排除对 Hb 重折叠过程的影响不显着。