DYNAMICS OF PROTEIN RNASE A & WATER-PROTEIN INTERACT AT DIFFERENT TEMPERATURES

这个子项目是许多研究子项目中的一个 由NIH/NCRR资助的中心赠款提供的资源。子项目和 研究者（PI）可能从另一个NIH来源获得了主要资金， 因此可以在其他CRISP条目中表示。所列机构为 研究中心，而研究中心不一定是研究者的研究机构。 已知蛋白质在环境压力下经受温度变化时经历“玻璃化转变”。这种转变涉及蛋白质分子的动力学及其酶活性。从晶体学Debye-Waller因子和蛋白质晶体结构出发，建立了蛋白质动力学与酶活性之间的关系。虽然人们普遍认为蛋白质的玻璃化转变与水化水密切相关，但其确切的机制尚不清楚。因此，我们的目标是了解这些确切的机制以及水和蛋白质分子之间的相互作用。在研究的第一步中，我们将从两种不同的母液中生长两种RNase A晶体，这两种母液对蛋白质分子施加了两种不同的溶剂环境。这些晶体的完整数据集将在98 K至320 K的9个温度点收集（每个点一个完整的数据集）。这两种晶体由于不同的溶剂环境而表现出不同的玻璃化转变行为，这将证实蛋白质动力学和水性质之间的关系。实验结果表明，我们的RNase A晶体具有良好的衍射质量。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Proteins are known to undergo `glass transition` when subjected to temperature variations at ambient pressure. This transition involves dynamics of protein molecules and their enzymatic activity. From crystallographic Debye-Waller factors and protein crystal structures, the relation between protein dynamics and enzymatic activity was established. Though it is widely accepted that protein glass transition is highly related to the hydration water, the exact mechanisms are still lacking. Therefore, our aim is to understand these exact mechanisms and the interactions between water and protein molecules. In the first step of the study, we will grow two kinds of RNase A crystals from two different mother liquors which impose two different solvent environments to protein molecules. The complete dataset for these crystals will be collected at 9 temperature points ranging from 98 K to 320 K (one complete dataset for each point). These two kinds of crystals are expected to exhibit different glass transition behaviors due to different solvent environments, which will confirm the proposed relation between protein dynamics and water properties. The previous experiments showed our RNase A crystals have good diffraction quality.