CHARACTERIZATION OF MAMMALIAN MITOCHONDRIAL RIBOSOMES

哺乳动物线粒体含有55S核糖体，其组成异常， 物理化学性质。拟议研究的目标是 阐明其结构、组成、功能和生物合成 哺乳动物线粒体核糖体。 从牛肝中大规模生产的线粒体核糖体正在被 在结构和功能上具有特征，为 哺乳动物线粒体核糖体的研究。单独的r-蛋白将是 根据它们的分子量、等电点、化学计量比、氨基 酸组成、N-末端氨基酸、胰蛋白酶多肽指纹图谱和 N-末端氨基酸序列。检查结构的方法 线粒体r蛋白的组织将包括：可及性 单体和亚核糖体颗粒中的R-蛋白到表面探针和 核心区颗粒和碎片中r-蛋白的鉴定 亚核糖体颗粒。识别单个r-蛋白的方法 已定义的功能域将包括蛋白质的功能重组 亚核糖体缺陷性颗粒及其位点特异性亲和力标记 探测器。哺乳动物线粒体r-蛋白的种间变异将 被分析以评估它们的快速进化分化。实验将会 也可以用来确定哪种线粒体r蛋白是由 线粒体和细胞质核糖体的特征 有丝分裂体蛋白的合成。

Mammalian mitochondria contain 55S ribosomes of unusual composition and physical-chemical properties. The goal of the proposed research is the elucidation of the structure, composition, function, and biosynthesis of mammalian mitochondrial ribosomes. Mitochondrial ribosomes produced on a large scale from bovine liver are being characterized structurally and functionally to provide a model system for the study of mammalian mitochondrial ribosomes. The individual r-proteins will be characterized with respect to their MW, isoelectric point, stoichiometry, amino acid composition, N-terminal amino acid, tryptic peptide fingerprint, and N-terminal amino acid sequence. Approaches to examine the structural organization of mitochondrial r-proteins will include: the accessibility of r-proteins in monoribosomes and subribosomal particles to surface probes and the identification of r-proteins in "core" particles and fragments of the subribosomal particles. Approaches to identify individual r-proteins within defined functional domains will include the functional reconstitution of protein deficient subribosomal particles and labelling with site-specific affinity probes. The interspecific variation of mammalian mitochondrial r-proteins will be analyzed to assess their rapid evolutionary divergence. Experiments will also be performed to ascertain which of the mitochondrial r-proteins are made in mitochondria and to characterize the cytoplasmic ribosomes involved in the synthesis of mitoribosomal proteins.