• 我要登录|
  • 免费注册
    |
  • 我的丁香通
    • 企业机构:
    • 成为企业机构
    • 个人用户:
    • 个人中心
  • 移动端
    移动端
丁香通 logo丁香实验_LOGO
搜实验

    大家都在搜

      大家都在搜

        0 人通过求购买到了急需的产品
        免费发布求购
        发布求购
        点赞
        收藏
        wx-share
        分享

        Purification of Mitochondria for Enzymes Involved in Nucleic Acid Transactions

        互联网

        710
        Ever since the demonstration that mitochondria contain DNA (mtDNA) and a complete apparatus for its replication and expression there has been an interest in identifying the enzymes involved in these processes. This problem is compounded by the fact that similar DNA transactions also occur in the nucleus, where vastly larger quantities of enzymes deal with 1000 times as much DNA. Thus, it has been a consistent challenge to the field to purify a distinct mitochondrial enzyme activity and prove that it is a bona fide mitochondrial enzyme. When mtDNA genomes were sequenced in the 1980s and open reading frames assigned to metabolic enzymes, it became clear that all proteins involved in mtDNA replication, transcription, and repair are products of nuclear genes that must be imported into mitochondria. Our laboratory has had a long-standing interest in these mitochondrial enzymes. When we first began to approach this problem, the best estimates in the literature were that the mtRNA polymerase had a molecular weight estimated at 66-68 kDa in rat liver (1 ) or 46 kDa in Xenopus oocytes (2 ); similarly, some early estimates of the size of mtDNA polymerase suggested that it was a homotetramer of 47-kDa subunits (3 ,4 ). Both the mtRNA polymerase and the catalytic subunit of DNA pol γ are now known to be approximately 125-140 kDa in various organisms (5 12 ). The possibility that proteolysis contributed to the early underestimate of the molecular masses of these proteins underscores the need to work quickly and to use a complete set of protease inhibitors during purification of these enzymes. In recent years, the effort to characterize the mitochondrial complement of DNA metabolic enzymes has benefited enormously from the expansion of genetic databases that provide a gold standard in quality control to assure that purified proteins have the properties predicted by primary sequence information.
        ad image
        提问
        扫一扫
        丁香实验小程序二维码
        实验小助手
        丁香实验公众号二维码
        扫码领资料
        反馈
        TOP
        打开小程序