STEROL BIOSYNTHESIS

甾醇生物合成

• 批准号: 6170487
• 负责人: SEIICHI P.T. MATSUDA
• 金额: $ 12.2万
• 依托单位: RICE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1997
• 资助国家: 美国
• 起止时间: 1997-07-01 至 2002-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6170487
• 关键词: Protista; enzyme inhibitors; lanosterol; microorganism metabolism; steroid biosynthesis; sterol esterase; yeasts

Protists cause numerous human diseases, including malaria, African sleeping sickness, Chagas' disease, leishmaniasis, giardiasis, and amebic meningitis. Treatments for each of these is inadequate, as few pharmaceutically exploitable metabolic differences have been found between humans and protists. Sterol biosynthesis is a promising but underexplored area for finding vital protist enzymes that lack human homologs, and the primary goal of this proposal is identifying novel drug targets in protist sterol metabolism. Animals and fungi synthesize the sterol ring system in one step using lanosterol synthase, which cyclizes oxidosqualene to lanosterol. The overwhelming majority of protists in which sterol biosynthesis has been examined synthesize that ring system in two steps: cycloartenol synthase cyclizes oxidosqualene to cycloartenol, which is then converted to lanosterol by cyclopropyl isomerase. These organisms should be susceptible to specific inhibitors of either cycloartenol synthase or cyclopropyl isomerase. Presented in this proposal are experiments to characterize these enzymes from several protists. A series of compounds designed to specifically inhibit cycloartenol synthase is described. Recombinant organisms that express the protist cycloartenol synthases and cyclopropyl isomerases will be constructed to provide enzymes with which to test the drug candidates. Metabolic research in pathogenic protists is hindered by difficulties in obtaining sufficient biomass for classical experiments with radiolabeled tracers. The approach described here uses molecular biological techniques to clone and express protist genes responsible for forming the sterol ring and to determine which pathway various protists use. This laboratory has constructed several metabolically engineered yeast strains in which the normal sterol pathway (which goes through lanosterol) is supplemented with components of the plant sterol biosynthetic pathway (which goes through cycloartenol). These strains can utilize either lanosterol or cycloartenol as sterol precursors, and will serve as hosts to clone cycloartenol synthase, cyclopropyl isomerase, or lanosterol synthase by genetic complementation.

原生生物引起许多人类疾病，包括疟疾、非洲疾病 昏睡病、恰加斯病、利什曼病、贾第鞭毛虫病和 阿米巴脑膜炎。 对每一种疾病的治疗都是不充分的，因为很少有 已发现可药用的代谢差异 人类和原生生物之间。 甾醇生物合成是一种很有前景但 寻找人类缺乏的重要原生生物酶的尚未开发的领域 同系物，该提案的主要目标是识别新的 原生生物甾醇代谢的药物靶点。动物和真菌合成 使用羊毛甾醇合酶一步合成甾醇环系统， 将氧化角鲨烯环化为羊毛甾醇。绝大多数 已经检查了甾醇生物合成的原生生物合成了 环系统分两步进行：环木菠萝烯醇合酶环化氧化角鲨烯 生成环木菠萝烯醇，然后通过环丙基转化为羊毛甾醇 异构酶。这些生物体应该对特定的抑制剂敏感 环木菠萝烯醇合酶或环丙基异构酶。 提出于 该提案是从几个方面表征这些酶的实验 原生生物。一系列旨在专门抑制 描述了环木菠萝烯醇合酶。表达的重组生物体 原生生物环木菠萝烯醇合酶和环丙基异构酶将是 构建用于提供测试候选药物的酶。 致病性原生生物的代谢研究因困难而受到阻碍 获得足够的生物量用于放射性标记的经典实验 示踪剂。 这里描述的方法使用分子生物学 克隆和表达负责形成的原生生物基因的技术 甾醇环并确定各种原生生物使用哪种途径。 本实验室构建了多种代谢工程酵母 正常甾醇途径（通过 羊毛甾醇）补充了植物甾醇的成分 生物合成途径（通过环木菠萝烯醇）。这些菌株 可以利用羊毛甾醇或环木菠萝烯醇作为甾醇前体，并且 将作为克隆环木菠萝烯醇合酶、环丙基的宿主 异构酶或羊毛甾醇合酶通过遗传互补。

项目成果

Cloning and characterization of the Dictyostelium discoideum cycloartenol synthase cDNA.

盘基网柄菌环木菠萝烯醇合酶 cDNA 的克隆和表征。

• DOI: 10.1007/s11745-000-0520-3
• 发表时间: 2000
• 期刊: Lipids
• 影响因子: 1.9
• 作者: Godzina,SM;Lovato,MA;Meyer,MM;Foster,KA;Wilson,WK;Gu,W;deHostos,EL;Matsuda,SP
• 通讯作者: Matsuda,SP

Steric bulk at position 454 in Saccharomyces cerevisiae lanosterol synthase influences B-ring formation but not deprotonation.

• DOI: 10.1021/ol9912940
• 发表时间: 2000-01
• 期刊: Organic letters
• 影响因子: 5.2
• 作者: B. M. Joubert;L. Hua;S. Matsuda