Crystal Aggregation in Kidney Stone

描述（由申请人提供）：肾结石形成为各种矿物质相的聚集体，但草酸钙一水合物（COM）是最常见的。以前的研究工作未能确定尿液测试，以确定结石形成者或有效的治疗方法，防止结石形成。我们假设，正常健康成人尿液中的大分子可以预防导致肾结石形成的病理性聚集事件，并且结石形成者在这种保护机制中表现出一些改变。在本修订申请中，我们建议通过具有两个特定目的的研究方案，使用本体结晶和显微表征方法的组合来鉴定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）使用先前建立的本体结晶方法研究单个大分子（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COM聚集过程的关键化学结构特征;（2）使用原子力显微镜直接测量目标1下研究的大分子对特定COM晶面粘附力的影响。在这些研究的后期阶段，我们将使用原子力显微镜直接测量溶液中各种大分子存在下取向晶体表面之间的粘附力。AFM的使用将提供关于含有特定化学官能团的大分子与所选COM表面的吸附的重要信息，这是无法以任何其他方式获得的。我们的初步数据表明，重要的面选择性结合和晶相和形态之间的相关性。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，其可以通过阻断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.