BIOLOGICAL METHYLATION OF CYTOCHROME C IN FUNGI & PLANTS

真菌中细胞色素 C 的生物甲基化

• 批准号: 3224625
• 负责人: WOON K PAIK
• 金额: $ 14.8万
• 依托单位: TEMPLE UNIV OF THE COMMONWEALTH
• 依托单位国家: 美国
• 财政年份: 1977
• 资助国家: 美国
• 起止时间: 1977-12-01 至 1987-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3224625
• 关键词: Euglena; NADPH cytochrome c2 reductase; Neurospora; affinity chromatography; chemical substitution; circular magnetic dichroism; cytochrome c; cytochrome oxidase; genetic translation; hemoprotein structure; high performance liquid chromatography; messenger RNA; methylation; methyltransferase; mitochondria; mutant; yeasts

The long term objectives of this program are to study the chemistry, enzymology and biological significance of protein methylation. In particular, cytochrome c methylation in fungi and plants will be used as a model system. This will be pursued with the following aims: (1) Exploration of the possible effects of methylation on various aspects of the in vitro translation of mRNA of yeast iso-l cytochrome c, employing the wheat germ extract in vitro translation system. In particular, the effect of methylation on (a) the completion of the polypeptide chain, (b) the rate of synthesis, (c) import into the mitochondria, and (d) the stability of the newly synthesized cytochrome c will be examined. (2) Studies on methylation-induced changes in cytochrome c conformation. Changes in tertiary structure by methyl and other chemical substituents will be monitored by pI value shift, optical rotatory dispersion and circular dichroism, thermal and acid-denaturation. (3) Comparative enzymological studies on methylated and unmethylated cytochrome c. This includes an assessment of the binding and catalytic activity towards cytochrome c reductase and oxidase, and cytochrome c peroxidase. (4) Identification, purification, and subsequent characterization of three enzymes implicated to exist from observations during the past grant period. (a) An enzyme which dealkylates methylated cytochrome c in vivo. (b) An enzyme which methylates the Res-86 lysine of cytochrome c. (c) Histone-specific protein methylase III from fungal or plant sources. (5) Identification of a mutant strain that is deficient in the cytochrome c methylation reaction in order to evaluate the reaction's physiological function in the organism, i.e., growth rate, the rate of respiration.

该计划的长期目标是研究化学， 蛋白质甲基化的酶学和生物学意义。 在 特别是，真菌和植物中的细胞色素 C 甲基化将被用作 模型系统。 此举将达到以下目标：（1） 探索甲基化对各个方面的可能影响 酵母 iso-l 细胞色素 c 的 mRNA 的体外翻译，采用 小麦胚芽提取物体外翻译系统。 特别是效果 甲基化对 (a) 多肽链的完成，(b) 的速率 合成，(c) 输入线粒体，以及 (d) 稳定性 将检查新合成的细胞色素c。 （二）研究 甲基化诱导的细胞色素c构象变化。 变化 由甲基和其他化学取代基组成的三级结构将是 通过 pI 值偏移、旋光色散和圆度监测 二色性、热变性和酸变性。 (3)比较酶学 甲基化和非甲基化细胞色素c的研究。 这包括一个 评估对细胞色素 c 的结合和催化活性 还原酶和氧化酶以及细胞色素c过氧化物酶。 (4) 身份证明， 涉及的三种酶的纯化和后续表征 根据过去资助期间的观察而存在。 （一）酶 它在体内使甲基化细胞色素 c 脱烷基化。 (b) 一种酶， 甲基化细胞色素 c 的 Res-86 赖氨酸。 (c) 组蛋白特异性蛋白 来自真菌或植物来源的甲基化酶 III。 (5) 突变体的鉴定 细胞色素 c 甲基化反应缺陷的菌株 评估反应在生物体中的生理功能，即 生长速率，呼吸速率。