BINDING ENERGY TRANSDUCTION IN ENZYMATIC CATALYSIS

酶配体结合能可以被用来驱动 催化步骤是一个被广泛接受的概念，但它还没有 容易受到直接实验测试的影响。我们发现了一个 谷氨酸的高道德两态宏观跃迁 脱氢酶及其复合体似乎是导致 大增量Cp的出现。我们开发了一个统一的模型 这解释了吡啶的各种热力学现象- 核苷酸脱氢酶。在此基础上，我们现在已经延长了 解释酶催化中自由能传递的模型。 在最近的工作中，我们发现不是一个单一的配体 结合诱导的转变，每种酶形式包含两种这样的 跃迁，每个跃迁都受一组给定的配体的影响。两个人 过渡以一种复杂的方式彼此耦合，并且它们的 能量学与热展开的能量学紧密相连。 蛋白质。利用最新可用的技术，我们希望获得 存在、性质和范围的确凿证据 这种转变的发生，发现它们的确切方式 耦合，并探索它们作为组件的可能功能 酶的能量转换机。

The idea that enzyme-ligand-binding energy can be utilized to drive catalytic steps is a widely held concept, but one that has not been susceptible to direct experimental testing. We have discovered a highly ethalpic two-state macroscopic transition in glutamate dehydrogenase and its complexes which appears to be responsible for the appearance of large deltaCp's. We have developed a unified model which explains a variety of thermodynamic phenomena of pyridine- nucleotide dehydrogenases. On this basis, we now have extended that model to account for free energy transduction in enzymatic catalysis. In more recent work we have found that rather than a single ligand binding induced transition, each enzyme form contains two such transitions, each affected by a given set of ligands. The two transitions are coupled to each other in a complex fashion and their energetics are tightly coupled to that of the thermal unfolding of the protein. Using newly available technology, we hope to obtain definitive evidence for the existence, nature, and scope of occurrence of such transitions, discover the precise manner of their coupling, and explore their possible function as components of the energy transduction machinery of enzymes.