AMINO ACID/PEPTIDE TRANSFER THERMODYNAMICS

我们两个小组将合作开发层析方法来 测量氨基酸分配，以更好地了解蛋白质 稳定性。目前的实验涉及液体油/水的分配 或结晶二酮基哌嗪溶解。但蛋白质核心既不是 既不像液体油，也不像结晶二肽。我们建议3个 层析方法：(1)有序油/水分配 在层析中，我们将独立控制 空间位阻和油中“液态-固体”的程度。 (2)反相氢键色谱，我们将在其中 对石油中的氢键能力有独立的控制 水相。(3)多肽相色谱，我们将在其中 将多肽而不是烷基链共价连接到二氧化硅载体上 用于氨基酸从水溶液中的分配。我们会 测量传递自由能、热焓、熵和热 氨基酸和多肽的能力。我们的目标是：(一)发展 比当前更接近蛋白质核心的分离介质 实验模型，以及(Ii)剖析氢键和硬脂酸 组份来自传递热力学。A(4)理论 组件将尝试从以下方面解释蛋白质的稳定性 这些和其他模型实验。一项理论工作也将评估 溶质和空穴形状对热力学分配的重要性 受限介质，如蛋白质和色谱柱。我们的 最终目标是利用这些氨基酸的分配研究和 帮助解开蛋白质背后驱动力的多肽 稳定性。

Our two groups will collaborate to develop chromatography methods to measure amino acid partitioning, to better understand protein stabilities. Current experiments involve liquid oil/water partitioning or crystal diketopiperazine dissolution. But protein cores are neither like liquid oils nor like crystalline dipeptides. We propose 3 chromatographic methods: (1) Ordered-Oil/Water Partitioning Chromatography, in which we will have independent control over the steric constraints and the degree of "liquidness-solidness" in the oil. (2) Reversed-Phase Hydrogen Bonding Chromatography, in which we will have independent control over the hydrogen bonding capacity in oil and aqueous phases. (3) Peptide Phase Chromatography, in which we will covalently attach peptides, rather than alkyl chains, to silica supports for the partitioning of amino acids from aqueous solvents. We will measure transfer free energies, enthalpies, entropies, and heat capacities for amino acids and peptides. Our goals are: (i) to develop partitioning media that more closely resemble protein cores than current experimental models, and (ii) to dissect hydrogen-bonding and stearic components from the transfer thermodynamics. A (4) Theoretical Component will attempt to interpret protein stabilities in terms of these and other model experiments. A theory effort will also assess the importance of solute and cavity shape for partitioning thermodynamics in constrained media, such as proteins and chromatography columns. Our ultimate goal is to use these partitioning studies of amino acids and peptides to help unravel the driving forces underlying protein stabilities.