Thermodynamics of Metal-Protein Interactions

有了这个奖项，化学部的生命过程化学计划正在资助达特茅斯学院的Dean Wilcox博士定量表征金属离子与蛋白质结合的热力学。 这项研究将提供洞察a）金属离子对蛋白质稳定性的贡献，和B）蛋白质对结合金属离子的氧化还原性质的调节。主要使用微量热法和蛋白质（位点特异性突变）和金属（例如，同构的Zn 2+、Co 2+、Cd 2+），将定量金属结合的热力学和熵组分，以及金属和蛋白质对金属蛋白稳定性的贡献。 此外，溶剂化对金属-蛋白质相互作用的贡献将通过确定溶剂对金属与蛋白质结合的热力学的影响来评估。 在这些方法的新应用中，当金属离子处于两种氧化态时，金属与蛋白质结合的热力学将被确定，并且由蛋白质调制的金属还原电位的熵和熵分量将被量化。金属起着至关重要的作用，包括结构作用，其中金属（通常是锌）有助于稳定蛋白质的活性形式，以及在基本反应中的催化作用，其中蛋白质调节金属（如铜）的化学性质。金属对蛋白质的稳定性以及蛋白质对金属离子性质的影响都将通过威尔科克斯和他的学生开创的实验方法和分析来量化。拟议的研究将寻求对蛋白质中所谓的结构金属的普遍性、位置和重要性的深入了解;这种深入了解可能会指导将金属离子工程化到治疗性蛋白质中，以增强稳定性。 相反，识别影响结合金属性质的蛋白质特征将有助于我们了解自然界如何控制和使用金属的独特反应。从事该项目的学生在无机，物理和生物化学之间的界面获得广泛的知识，并学习对科学和教育事业重要的技能。

With this award, the Chemistry of Life Processes Program in the Chemistry Division is funding Dr. Dean Wilcox from Dartmouth College to quantitatively characterize the thermodynamics of metal ion binding to proteins. This research will provide insight in a) the contributions of metal ions to the stability of proteins, and b) the modulation by the proteins of the redox properties of bound metal ions. Using primarily microcalorimetry methods and systematic perturbations of the protein (site specific mutations) and of the metal (e.g., isostructural Zn2+, Co2+, Cd2+), the enthalpic and entropic components of the metal binding will be quantified, as will be the metal and the protein contributions to the stability of the metalloprotein. Additionally, the contribution of solvation to metal-protein interactions will be evaluated by determining solvent effects on the thermodynamics of metal binding to the protein. In a novel application of these methods, the thermodynamics of metal binding to a protein will be determined when the metal ions is in two oxidation states, and the enthalpic and entropic components of the metal reduction potential, which is modulated by the protein, will be quantified.Essential trace metals are normally bound to proteins in living organisms. The metals play crucial roles, including a structural role, where the metal (often zinc) helps to stabilize the active form of a protein, and a catalytic role in essential reaction, where the protein tunes the chemical properties of a metal (such as copper). Both the stabilization of a protein by a metal and the influence by a protein of the properties of metal ion will be quantified with experimental methods and analysis pioneered by Wilcox and his students. The proposed research will seek insight in the prevalence, placement and importance of so-called structural metals in proteins; this insight may guide the engineering of metal ions into therapeutic proteins for enhanced stability. Conversely, the identification of the features of a protein that influence the properties of a bound metal will help us to understand how Nature controls and uses the unique reactions of metals. Students working on this project gain extensive knowledge at the interface between inorganic, physical and biochemistry and learn skills important for careers in science and education.