De-orphanizing MMPs in intercelluar interactions

项目总结 几乎所有人类疾病都涉及蛋白分解途径，包括癌症、血栓形成、 关节炎、感染、炎症和阿尔茨海默氏症。许多这样的乳沟活动都是在 细胞之间的界面，它们调节细胞内的相互作用，特别是那些由基质驱动的相互作用 金属蛋白酶(MMPs)。关于这些蛋白水解酶的论文已经发表了40,000多篇，而“基质金属蛋白酶”是 美国国立卫生研究院目前资助的400多项拨款的主题。这一庞大的作品包含了重要的信息， 但在这一点上，任何一本关于MMPs的出版物都只是逐渐地提高了我们的知识。事实上，对于 “流行的”MMP，收集的许多信息是相互冲突的，提出的问题多于答案。 然而，另一方面，近一半的基质金属蛋白酶家族的底物甚至还没有确定。 该项目的长期目标是通过建立一个主要的 我们对指导基质金属蛋白酶底物选择性的结构-功能关系的理解取得了进展。 为了实现这一目标，我们将在系统水平上研究基质金属蛋白酶的结构和功能。与其尝试 为了了解一种基质金属蛋白酶是如何切割底物的，我们将定量地描述该家族中的每一种蛋白酶是如何 识别并切割其底物。 该项目的具体目标是检验以下假设：1)每个特性决定 在基质金属蛋白酶催化结构域中的位置对底物选择性有不同的贡献，2) 通过在子站点上放置知识，可以预测MMPs的生理(和病理生理)底物 3)MMPHopexin(HPX)结构域调节 不会改变底物的识别和选择性。 本研究的结果将为在生物学上理解基质金属蛋白酶的功能提供必要的基础 以及系统层面的病理学。这项研究将揭示专业化和扩张的结构基础 功能，这仍然是生物学中最重要的悬而未决的问题之一。这项工作还将揭示一种 许多新的治疗靶点，因为底物是基质金属蛋白酶活性的真正下游效应器。 此外，这项研究还将产生对单个基质具有高度选择性的多肽底物 金属蛋白酶。这些底物可以用来设计试剂，以成像动物和 人类。同样的底物也可以用来制造靶向药物输送载体。最后，所有 来自研究的信息，计算工具，结果，预测，蛋白质组分析和 解释将存放在我们的蛋白质分解地图网站(www.proteolysis.org)上，供科学研究人员使用 和医学界。

PROJECT SUMMARY Proteolytic pathways are involved in virtually every human disease including, cancer, thrombosis, arthritis, infection, inflammation, and Alzheimer's disease. Many of these cleavage events take place at the interface between cells, and they regulate intracellular interactions, especially those driven by the matrix metalloproteinases (MMPs). More than 40,000 papers have been published on these proteases, and “MMP” is topic of more than 400 currently funded NIH grants. This massive body of work contains important information, but at this point any single publication on MMPs advances our knowledge only incrementally. In fact, for the “popular” MMPs, much of the information being collected is conflicting, raising more questions than answers. On the other hand though, substrates have not even been identified for nearly one-half of the MMP family. The long-term objective of this project is to shift the paradigm in MMP research by making a major advance in our understanding of the structure-function relationships that guide substrate selectivity of the MMPs. To accomplish this objective we will study MMP structure and function at the systems level. Rather than trying to understand how one MMP cleaves a substrate, we will quantitatively describe how every protease in the family recognizes and cleaves its substrates. The Specific Aims of the project are to test the following hypotheses: 1) that each specificity determining position within the MMP catalytic domain makes a different contribution to substrate selectivity, 2) that physiologic (and pathophysiologic) substrates of the MMPs can be predicted by placing knowledge on subsite specificity at the catalytic cleft into physiologic context, 3) that the MMP hemopexin (HPX) domain modulates but does not alter substrate recognition and selectivity. The outcome of the study will provide the essential foundation for understanding MMP function in biology and pathology at the systems level. The study will reveal the structural basis for specialization and expansion of function, which remains one of the most important unanswered questions in biology. The work will also reveal a host of new therapeutic targets because the substrates are the real downstream effectors of MMP activity. Additionally, the study will generate peptide substrates that are highly selective for individual matrix metalloproteinases. These substrates can be used to devise agents to image proteolysis in animals and in humans. The same substrates could also be employed to create targeted drug delivery vehicles. Finally, all information derived from the study, computational tools, results, predictions, proteomic analysis and interpretations will be deposited on our Proteolysis MAP website (www.proteolysis.org) for use by the scientific and medical community.