Laboratory for Molecular Sensing, IBP-CNR, Naples, Italy.
Arch Biochem Biophys. 2012 Sep 1;525(1):40-6. doi: 10.1016/j.abb.2012.05.019. Epub 2012 Jun 5.
The structural and stability properties of a novel zinc-dependent alcohol dehydrogenase from the hyperthermophilic archaeon Pyrobaculum aerophilum (PyAeADHII) were investigated by Fourier transformed infrared spectroscopy (FTIR). This enzyme is a thermostable homo-tetramer belonging to the GroES-fold motif proteins characterized by an irregular β-barrel conformation. Our results revealed a protein with a secondary structure rich in β-sheet (32% of the total secondary elements) and it showed a three-step thermal unfolding pathway. The complete enzyme denaturation was preceded by the formation of a relaxed tertiary/quaternary structure and previously by an excited native-like conformation. Two-dimensional correlation spectroscopy analysis (2D-COS) and differential scanning calorimetry (DSC) experiments supported these data and allowed us to determine the protein melting temperature at 96.9 °C as well as to suggest the sequence of the events that occurred during the protein denaturation process.
采用傅里叶变换红外光谱（FTIR）研究了来自嗜热古菌 Pyrobaculum aerophilum（PyAeADHII）的新型锌依赖性醇脱氢酶的结构和稳定性特性。该酶是一种热稳定的同型四聚体，属于 GroES 折叠基序蛋白，其特征为不规则的β-桶构象。我们的结果表明，该蛋白具有富含β-折叠（占总二级元件的 32%）的二级结构，并显示出三步热解折叠途径。完整酶的变性先于松弛的三级/四级结构的形成，之前是激动的类似天然构象。二维相关光谱分析（2D-COS）和差示扫描量热法（DSC）实验支持了这些数据，并允许我们确定蛋白的熔点为 96.9°C，同时还提示了蛋白变性过程中发生的事件的顺序。
