BIO-ENGINEERING OF COMPOUNDS ACTIVE AGAINST MDR CANCER

有效对抗耐多药癌症的化合物的生物工程

基本信息

批准号：
6260415
负责人：
Nigel D PRIESTLEY
金额：
$ 7.91万
依托单位：
UNIVERSITY OF MONTANA
依托单位国家：
美国
项目类别：
财政年份：
1998
资助国家：
美国
起止时间：
1998-04-01 至 2003-03-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/6260415
关键词：
P glycoprotein Streptomyces antineoplastic antibiotics drug design /synthesis /production macrolide antibiotics microorganism metabolism multidrug resistance

P glycoprotein Streptomyces antineoplastic antibiotics drug design /synthesis /production macrolide antibiotics microorganism metabolism multidrug resistance

项目摘要

DESCRIPTION: Nonactin is an inhibitor of the 170-kDa-P-glycoprotein mediated efflux of 4'-O-tetrahydropyranyladriamycin in multi-drug resistant erythroleukemia K562 cells. Nonactin and its macrotetrolide homologues are als active against cancer cell lines in vitro and have shown tumor reducing activity in in vivo studies with mice. Further, the macrotetrolides act as typical ionophore antibiotics being effective against Gram+ bacteria, fungi, and mycobacteria. Nonactin is not a current drug candidate because of its relatively high toxicity. The naturally occurring homologues, however, have greater activity than nonactin: from a QSAR analysis we propose a series of ne compounds which have potentially much higher activity. Chemical synthesis of macrotetrolide homologues is not trivial as it requires the separate synthesis of both enantiomers of nonactic acid; selective assembl of nonactic acid units into a tetrameric intermediate; and finally a macrolactonization reaction to form the macrotetrolide ring. Streptomyces griseus strain ETH A7796, in comparison, can readily make over 1 gL-1 of nonactin in fermentation. We propose to combine the best aspects of chemical synthesis and 'biosynthesis' to make new macrotetrolides. Chemical synthesis will be used to make racemic nonactic acid analogs via established, efficient routes. 'Biosynthesis' in a genetically altered strain of S. griseus will achieve the stereospecific biotransformation of the nonactic acid analogs into new macrotetrolides. The specific aims of this proposal are: 1. To purify from S. griseus ETH A7796 and characterize the key enzyme in nonactin biosynthesis, nonactate synthase, which catalyzes the conversion of a acyclic precursor into nonactic acid. 2. To isolate and characterize genes of the nonactin biosynthesis cluster. 3. To use a mutant strain, disrupted in nonactin biosynthesis, to make four prototypical macrotetrolide analogs, and to study their physical and biologica properties.

描述：非肌动蛋白是170-KDA-P-糖蛋白的抑制剂多药耐药物中4'-O-四氢吡喃基甲霉素的介导的外排红血球血清K562细胞。非肌动蛋白及其大型二烯丙基同源物是 ALS在体外对癌细胞系进行活性，并显示出还原性的肿瘤小鼠体内研究的活性。此外，大型二烯酸酯充当典型的离子机抗生素可有效地针对革兰氏+细菌，真菌，和分枝杆菌。非肌动蛋白不是目前的候选药物毒性相对较高。但是，天然存在的同源物具有比非肌动蛋白更大的活性：从QSAR分析中，我们提出了一系列具有更高活性的NE化合物。化学合成大型二烯丙基同源物并非微不足道需要单独的非肌酸对映异构体的合成；将非活性酸单位的选择性组装成四聚体中间体；和最后，大肠杆菌化反应形成了大型二酰甲环。相比之下，链霉菌菌株A7796可以很容易地推动发酵中非肌肉蛋白的1 GL-1。我们建议结合最佳方面化学合成和“生物合成”以制造新的大型二酚。化学合成将用于通过建立，高效的路线。遗传改变的“生物合成” S. griseus的菌株将实现立体特异性的生物转化非活性酸类似物进入新的大型二烯酸酯。该提案的具体目的是： 1。从S. griseus eth a7796纯化并表征了键酶非肌动蛋白生物合成，非活性合酶，催化的转化无环性前体进入非活性酸。 2。分离和表征非肌动蛋白生物合成簇的基因。 3。使用在非肌动蛋白生物合成中破坏的突变株，使四个典型的大型二烯酸类似物，并研究其物理和生物学特性。