STRUCTURE/FUNCTION OF GLUTATHIONE S-TRANSFERASE SYSTEMS

我们的目标是提供详细的结构信息，通过 系统的晶体学研究，理解 谷胱甘肽S-转移酶的构效关系 提供对致癌基因毒性亲电体的保护。 GST 也被发现与人的寿命和衰老密切相关。 雌性小鼠，其中GST水平降低与 随着年龄的增长，对疾病和药物的敏感性增加。 也有人认为，商品和服务税在 对寄生虫免疫防御。 大鼠、小鼠和狒狒的疫苗接种 链球菌Mansoni GST导致蠕虫的显著减少 人口。 近年来，也有人提出，GST是 在一些肿瘤细胞中负责耐药性。 因此， 这个酶家族的结构-功能关系可能具有 对理解与预防有关的问题的长期意义 癌症、控制肿瘤、治疗寄生虫病，以及 了解衰老过程中的压力。 最近，我们在 μ-类GST转化为四种不同的晶体形式，并获得了晶体 四种人类α级GST，总共八种晶体形态。 我们现在已经解决了五个这些晶体形式的结构， 分子置换法 在本提案中，我们计划完善这些 晶体结构 我们的目标是比较它们的结构， 鉴定由于底物结合引起的构象变化。 我们的目标 为了定位亲电子底物的结合位点，其位置 目前尚不清楚。 我们计划比较 不同类别的GST。 此外，我们还计划将 解决果蝇GST的结构，其中一个具有序列 与E.杆菌 我们还计划 结晶并研究GST的突变结构。 拟议 研究可以回答许多关于结构的关键问题- GST的功能。 它也将增加我们对 大分子识别的分子基础。

Our objective is to provide detailed structural information, through systematic crystallographic investigations, necessary in understanding the structure-function relationship of the glutathione S-transferase provide protection against cancer-causing genotoxic electrophiles. GST is also found to be closely related to the lifespan and aging of the female mouse, where a reduced GST level was implicated to be related to increased susceptibility to disease and drugs occurring with advance age. It has also been suggested that GSTs play a pivotal function in the immuno defense against parasites. Vaccinations of rats, mice and baboons with S. Mansoni GST have resulted in a significant reduction of the worm populations. In recent years it has also been suggested that GST is responsible for drug resistance in some tumore cells. Thus a knowledge of the structure-function relationship of this family of enzymes may have long-term significance in understanding problems related to prevention of cancer, control of tumors, treatment of parasitic diseases, and understanding of stress in the aging process. We have recently grown a mu-class GST into four different crystal forms and have obtained crystals for four humanalpha-class GSTs, making a total of eight crystal forms. W have now solved the structures of five of these crystal forms by molecular replacement methods. In this proposal we plan to refine these crystal structures. We aim to compare their structures in order to identify the conformational changes due to the substrate binding. We aim to locate the binding site for the electrophilic substrates,its location is unknown at the present. We plan to compare the structures among different classes of GSTs. In addition, we plan to crystallize and to solve the structures of Drosophila GSTs, one of which has sequence homology to the stringent starvation protein of E. coli. We also plan to crystallize and study the mutant structures of GSTs. The proposed research could answer many of the key questions about the structure- function of GST. It will also increase our knowledge concerning the molecular basis of macromolecular recognition in general.