POLYAMINES IN TRYPANOSOMES - FUNCTION AND METABOLISM

多胺是所有细胞共有的低分子量化合物， 对生长和分化至关重要，作为辅助因子， 大分子合成和稳定核酸。 本研究旨在 a）探索多胺和相关核苷合成的调节， 致病性非洲锥虫; B）确定多胺在 这些寄生虫; c）开发新型单一药物和联合化疗 掺入多胺拮抗剂; d）使多胺拮抗剂的变化与多胺拮抗剂的变化相关。 合成到锥虫B的生命周期阶段。布鲁塞。 这项研究将利用我们的初步发现，其中一个具体的 多胺拮抗剂，DL-α-二氟甲基鸟氨酸（DFMO）治愈 短期小鼠感染，和DEMO+抗肿瘤剂博来霉素治愈 长期中枢神经系统感染。 多胺代谢的关键酶是 鸟氨酸脱羧酶（ODC），DFMO的靶标。 由于ODC活动 在大多数细胞中受到仔细调控，该研究将检查ODC诱导， 本发明涉及通过作图的血流/培养锥柄线虫转化， ODC在继代培养时的血流形式发生变化，在较低的 锥虫 一种多胺活化的蛋白激酶，磷酸化 T. B.布鲁氏菌将作为ODC调节剂进行检查。 一 多胺合成的副产物甲硫腺苷（MTA）可能是关键 用于回收腺嘌呤和蛋氨酸。 这一途径中的关键酶MTA 磷酸化酶将在T. B.布氏杆菌的新抑制剂， 酶和MTA分解的中间产物。 锥虫DNA聚合酶是多胺活化的。 他们的互动 以kDNA为模板引物， 模拟多胺，将被检查。 为了指导联合化疗， 多胺耗竭对寄生虫摄取 多胺类抗肿瘤剂和其他药物将被确定。 这些研究将在体内、体外（全细胞）、粗品和 纯化酶的研究，并采用放射性示踪技术，以及 薄层和高精度液相色谱法。 离子交换和 亲和层析法可用于ODC、蛋白激酶和DNA的分离 聚合酶研究。 我们将进一步研究多胺阳离子药物 通过与阳离子抗肿瘤剂+联合治疗的体内相互作用 多胺拮抗剂 我们希望借此发现更多的目标， 本发明的目的是提供一种用于化疗的新的药剂或药剂组合， 用于人类和兽用锥虫病。

Polyamines, low molecular weight compounds common to all cells, are essential to growth and differentiation, acting as cofactors in macromolecular synthesis and stabilizing nucleic acids. This study aims to a) explore regulation of synthesis of polyamines and related nucleosides in pathogenic African trypanosomes; b) ascertain functions of polyamines in these parasites; c) develop novel single drug and combination chemotherapy incorporating polyamine antagonists; d) correlate changes in polyamine synthesis to life-cycle stages of Trypanosoma b. brucei. The research will exploit our preliminary findings in which a specific polyamine antagonist, DL-Alpha-difluoromethylornithine (DFMO) cured a short-term murine infection, and DEMO + the antitumor agent bleomycin cured a long term CNS infection. A key enzyme of polyamine metabolism is ornithine decarboxylase (ODC), the target of DFMO. Since ODC activity is carefully regulated in most cells, the study will examine ODC induction as it relates to bloodstream/culture trypomostigote transformation by charting ODC changes in bloodstream forms on subculture, and also in a lower trypanosomatid. A polyamine-activated protein kinase, phosphorylating an endogenous substrater in T. b. brucei will be examined as ODC regulator. A byproduct of polyamine synthesis, methylthioadenosine (MTA), may be crucial for recycling adenine and methionine. A key enzyme in this pathway, MTA phosphorylase will be studied in T. b. brucei, as will novel inhibitors of the enzyme, and intermediates in MTA breakdown. Trypanosomatid DNA plymerases are polyamine-activated. Their interaction with kDNA as template primers, and effects of cationic trypanocides which mimic polyamines, will be examined. To guide combination chemotherapy, effects of polyamine depletion of the the parasite on uptake of polyamine-like antitumor and other agents will be determined. These studies will correlate in vivo, in vitro (whole cell), crude and purified enzyme studies, and employ radio-tracer techniques as well as thin-layer and high-precision liquid chromatography. Ion-exchange and affinity chromatography would be used in ODC, protein kinase and DNA polymerase studies. We would further investigate polyamine-cationic drug interaction in vivo by combination therapy with cationic antitumor agents + polyamine antagonists. We hope thereby to uncover additional targets for chemotherapy and to develop novel agents or combinations of agents useful for human and veterinary trypanosomiases.