Crystal Aggregation in Kidney Stone

描述(申请人提供)：肾结石形成为各种矿物相的集合体，但最常见的是一水草酸钙(COM)。以前的研究工作既没有确定尿液测试来识别结石形成者，也没有找到有效的预防结石形成的疗法。我们假设，正常健康成年人尿液中的大分子可以阻止导致肾结石形成的病理性聚集事件，而结石形成者在这种保护机制中表现出一些变化。在这个修订的应用中，我们建议使用整体结晶和微观表征方法相结合的方法，通过具有两个特定目标的研究协议来识别导致聚集抑制缺陷的大分子的特定化学结构特征。这两个具体目标是：(1)使用以前建立的本体结晶方法来研究单个大分子(来自生物或化学来源)以及聚阴离子和聚阳离子的组合，以确定对COM聚集过程至关重要的化学结构特征；(2)使用原子力显微镜直接测量在目标1下研究的大分子对特定COM晶面粘附力的影响。在这些研究的后续阶段，我们将使用原子力显微镜来直接测量在溶液中存在各种大分子时取向晶体表面之间的粘附力。原子力显微镜的使用将提供有关含有特定化学官能团的大分子在选定的COM表面上的吸附的重要信息，这是任何其他方式都无法获得的。我们的初步数据显示，表面选择性结合与晶相和形态之间存在重要的相关性。将特定化学官能团的连接延伸到聚集过程，将允许智能设计药物，通过阻止聚集过程来防止结石形成。

DESCRIPTION (provided by applicant): Kidney stones form as aggregates of various mineral phases, but calcium oxalate monohydrate (COM) is the most prevalent. Prior research efforts have failed to identify either a urine test that identifies stone formers or effective therapies preventing stone formation. We hypothesize that macromolecules in the urine of normal healthy adults prevent the pathologic aggregation events that lead to kidney stone formation, and that stone formers manifest some alteration in this protective mechanism. In this revised application, we propose to use a combination of bulk crystallization and microscopic characterization methods to identify specific chemical structural features of macromolecules that lead to a defect in aggregation inhibition, through a research protocol with two Specific Aims. The two Specific Aims are: (1) to use previously established bulk crystallization methods to study single macromolecules (from either biological or chemical origins) and combinations of polyanions and polycations to identify the chemical structural features critical to the COM aggregation processes and (2) to use atomic force microscopy to directly measure the influence of macromolecules studied under Aim 1 on the force of adhesion at specific COM crystal faces. In the later phases of these studies, we will use atomic force microscopy to measure directly the adhesion force between oriented crystal surfaces in the presence of various macromolecules in solution. The use of AFM will provide important information about the adsorption of macromolecules containing specific chemical functional groups with selected COM surfaces, that is not obtainable in any other way. Our preliminary data have shown important correlations between face selective binding and crystal phase and morphology. Extending the linkage of specific chemical functional groups to the aggregation process will allow for the intelligent design of drugs that could prevent stone formation by blocking aggregation processes.