SPERMIDINE SYNTHASE

该子项目是利用NIH/NCRR资助的中心赠款提供的资源的许多研究子项目之一。子项目和研究者（PI）可能从另一个NIH来源获得主要资金，因此可以在其他CRISP条目中表示。所列机构为中心，不一定是研究者所在机构。我们的目的是表征大肠杆菌亚精胺合酶（SpeE）的三维结构，并进行这种酶的功能研究。SpeE催化亚精胺的合成，亚精胺是一种已知的多胺。多胺如腐胺、亚精胺和精胺是在活生物体中大量存在的聚阳离子和线性脂肪族化合物。它们中和细胞内的聚阴离子，特别是DNA，因此为细胞中的DNA分子提供稳定性。它们也是DNA、RNA和蛋白质合成的重要因子。多胺能刺激细菌生长。在癌组织中也观察到多胺积累。抑制多胺的生物合成和耗尽细胞内多胺含量已成为治疗细菌感染和癌症的潜在治疗方法。SpeE的结构和功能表征是至关重要的，因为这些研究将有助于合理设计抑制该酶的潜在药物。

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. We aim to characterize the three-dimensional structure of Escherichia coli spermidine synthase (SpeE) and to carry out functional studies for this enzyme. SpeE catalyzes the synthesis of spermidine, which is a known polyamine. Polyamines such as putrescine, spermidine and spermine, are polycationic and linear aliphatic compounds present in significant amount in living organisms. They neutralize intracellular polyanions, especially DNA and therefore providing stability for DNA molecules in the cell. They are also known to be important factors of DNA, RNA and protein synthesis. Bacteria growth is stimulated by polyamines. Polyamines accumulation has also been observed in cancerous tissues. Inhibition of polyamine biosynthesis and depletion of intracellular polyamine content has become a potential therapeutic method for the treatment of bacterial infection and cancer. Structure and functional characterization of SpeE is crucial as these studies will facilitate the rational design of such potential drugs that inhibit the enzyme.