LEISHMANIA MEXICANA ALDOLASE INHIBITION STUDIES

本子项目是利用由NIH/NCRR资助的中心赠款提供的资源的众多研究子项目之一。子项目和研究者（PI）可能已经从另一个NIH来源获得了主要资金，因此可以在其他CRISP条目中表示。列出的机构是中心的，不一定是研究者的机构。由于寄生虫病，第三世界国家正处于危机之中。一种主要疾病是由锥虫引起的，锥虫是一种单细胞生物，完全依靠糖酵解来满足其代谢能量需求。我们的方法是使用针对糖酵解酶的抑制剂来停止糖酵解。酶的靶标是果糖-1,6-二磷酸醛缩酶，因为它在糖酵解途径中处于关键位置。我们的模型酶是结构已解的墨西哥利什曼原虫醛缩酶。其催化位点的不同之处在于一个关键的丙氨酸残基取代了在哺乳动物醛缩酶中观察到的甘氨酸残基。对哺乳动物酶的研究将假定的丙氨酸放置在一个底物（果糖-1,6-二磷酸）磷酸结合位点附近，暗示了寄生虫和哺乳动物醛缩酶之间的结合差异。我们项目的目标是解决墨西哥利什曼原虫醛缩酶配体复合物的结构，并将这些复合物的结构与哺乳动物醛缩酶结合的底物/抑制剂进行比较。使用ADSC 3x3探测器在X29收集数据使我们能够以最大分辨率收集数据，否则由于我们的晶体中有很长的单位胞尺寸而不可能。我们建议收集几个反应配合物的高分辨率数据，从这些数据中设计基于机制的先导化合物，这些先导化合物将通过反复的晶体结构测定来优化。

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. Third world countries are in a crisis situation because of parasitic diseases. A major disease is caused by trypanosomatids, unicellular organisms that rely solely on glycolysis to meet their metabolic energy demands. Our approach is to use inhibitors directed against glycolytic enzymes to stop glycolysis. The enzyme target is fructose-1,6-biphosphate aldolase because of its key-position in the glycolysis pathway. Our model enzyme is Leishmania mexicana aldolase whose structure is already solved. Its catalytic site differs by a critical alanine residue that replaces a glycine residue observed in mammalian aldolases. Studies on the mammalian enzyme places the putative alanine near one of the substrate (fructose-1,6-bisphosphate) phosphate binding sites alluding to binding differences between parasite and mammalian aldolases. The goal of our project is to solve the structure of Leishmania mexicana aldolase-ligand complexes and to compare the structure of these complexes with substrate/inhibitors bound in mammalian aldolases. Data collection at X29 using the ADSC 3x3 detector has allowed us to collect data to maximum resolution otherwise not possible because of a long unit cell dimension in our crystals. We propose to collect high resolution data on several reaction complexes from which to design mechanism based lead compounds that will be optimized through iterative rounds of crystal structure determination.