Gelpi C, Rodriguez-Sanchez J L, Hardin J A
Department of Immunology, San Pablo Hospital, Barcelona, Spain.
Clin Exp Immunol. 1988 Feb;71(2):281-8.
HnRNP antigen from HeLa cells was purified using a monoclonal antibody (383 IgM) that recognizes heterogeneous nuclear ribonucleoprotein (hnRNP). From extracts of HeLa cells radiolabelled with 32P, this antibody immunoprecipitates relatively large RNAs of heterogeneous size which are synthesized in the presence of actinomycin D at doses which suppress synthesis of ribosomal RNAs (characteristic features of heterogeneous nuclear RNA). In immunoblots, 383 IgM binds to seven polypeptides: one of approximately 23,000 daltons, three between 30,000 and 43,000 daltons which correspond to the known hnRNP polypeptides called A1, A2 and C1, one of approximately 50,000 daltons, and a doublet of approximately 120,000 daltons. These proteins comigrate through sucrose density gradients suggesting that they are physically associated. Thus, 383 IgM appears to define an epitope that is shared among a number of the protein components of hnRNP. This antibody has been used to design a simple and fast protocol which allows the determination of autoantibodies from human sera by ELISA.
利用一种识别不均一核核糖核蛋白（hnRNP）的单克隆抗体（383 IgM），从HeLa细胞中纯化出hnRNP抗原。在以32P进行放射性标记的HeLa细胞提取物中，该抗体免疫沉淀出大小不均一的相对较大的RNA，这些RNA是在放线菌素D存在的情况下合成的，放线菌素D的剂量能够抑制核糖体RNA的合成（不均一核RNA的特征）。在免疫印迹中，383 IgM与七种多肽结合：一种约23,000道尔顿，三种在30,000至43,000道尔顿之间，它们对应于已知的hnRNP多肽A1、A2和C1，一种约50,000道尔顿，以及一组约120,000道尔顿的双峰。这些蛋白质在蔗糖密度梯度中一起迁移，表明它们在物理上相互关联。因此，383 IgM似乎定义了一个在hnRNP的许多蛋白质成分中共享的表位。该抗体已被用于设计一种简单快速的方案，通过ELISA来测定人血清中的自身抗体。
