BINDING ENERGY TRANSDUCTION IN ENZYMATIC CATALYSIS

酶-配体结合能可以用来驱动 催化步骤是一个广泛持有的概念，但尚未被广泛接受。 易于直接实验测试。 我们已经发现了一种 谷氨酸盐高致死性两态宏观跃迁 脱氢酶及其复合物似乎是负责 出现大的Δ Cp。 我们开发了一个统一的模型 它解释了吡啶的各种热力学现象， 核苷酸酶。 在此基础上，我们现在已经扩大了， 模型来解释酶催化中的自由能传递。 在最近的工作中，我们发现， 结合诱导的转变，每种酶形式含有两个这样的 跃迁，每一个都受一组给定的配体的影响。 两 转换以复杂的方式彼此耦合，并且它们的 能量学与热解折叠紧密耦合， 蛋白质。 利用新技术，我们希望获得 的存在，性质和范围的明确证据， 这种转变的发生，发现他们的确切方式， 耦合，并探讨其作为组件的可能功能， 酶的能量传递机制。

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.