Thermostability of Refolded Ovalbumin and S-Ovalbumin
Thermostability of Refolded Ovalbumin and S-Ovalbumin
复制标题
DOI：
10.1271/bbb.69.922
复制
发表时间：
2005-01
期刊：
影响因子：
--
通讯作者：
N. Takahashi;M. Onda;K. Hayashi;M. Yamasaki;T. Mita;M. Hirose
中科院分区：
文献类型：
--
作者：
N. Takahashi;M. Onda;K. Hayashi;M. Yamasaki;T. Mita;M. Hirose
卵白蛋白是丝氨酸蛋白酶抑制剂超家族的成员，在带壳蛋的储存过程中或通过对分离的蛋白质进行碱处理（ΔTm =8 °C），卵白蛋白转化为热稳定形式S-卵白蛋白。作为S-卵白蛋白的结构特征，三个丝氨酸残基（Ser 164、Ser 236和Ser 320）呈现D-氨基酸残基构型，而与非热稳定的天然卵白蛋白相比的构象变化非常小（Yamasaki，M.，Takahashi，N.，和Hirose，M.，J. Biol. Chem.，278，35524-35530（2003））。为了评估结构特征对蛋白质热稳定性的作用，将卵清蛋白和S-卵清蛋白变性以消除构象调节效应，然后重新折叠。变性卵清蛋白和S-卵清蛋白正确地复性为具有相应差异热稳定性的原始非变性形式。卵清蛋白和S-卵清蛋白的天然和重折叠形式的二硫键结构基本上没有差异。这些数据是一致的观点，即构型反转，这是唯一的化学修饰直接检测到的S-卵清蛋白到目前为止，卵清蛋白的热稳定性中起着核心作用。S-卵白蛋白的重折叠速率大于卵白蛋白，表明参与，至少部分地，增加的折叠速率的热力学稳定。
Ovalbumin, a member of the serpin superfamily, is transformed into a thermostabilized form, S-ovalbumin, during storage of shell eggs or by an alkaline treatment of the isolated protein (ΔTm =8 °C). As structural characteristics of S-ovalbumin, three serine residues (Ser164, Ser236 and Ser320) take the D-amino acid residue configuration, while the conformational change from non-thermostabilized native ovalbumin is very small (Yamasaki, M., Takahashi, N., and Hirose, M., J. Biol. Chem., 278, 35524–35530 (2003)). To assess the role of the structural characteristics on protein thermostabilization, ovalbumin and S-ovalbumin were denatured to eliminate the conformational modulation effects and then refolded. The denatured ovalbumin and S-ovalbumin were correctly refolded into the original non-denatured forms with the corresponding differential thermostability. There was essentially no difference in the disulfide structures of the native and refolded forms of ovalbumin and S-ovalbumin. These data are consistent with the view that the configuration inversion, which is the only chemical modification directly detected in S-ovalbumin so far, plays a central role in ovalbumin thermostabilization. The rate of refolding of S-ovalbumin was greater than that of ovalbumin, indicating the participation, at least in part, of an increased folding rate for thermodynamic stabilization.