Hobart M J, Fernie B A, Stanley K K, Lachmann P J
Molecular Immunopathology Unit, M.R.C. Centre, Cambridge, U.K.
Proc Biol Sci. 1993 May 22;252(1334):157-62. doi: 10.1098/rspb.1993.0060.
A cDNA clone which directs the expression of a fusion protein reacting with anti-C6 antibodies has been isolated and sequenced. A synthetic peptide corresponding to the 14 C-terminal residues of the expressed protein elicited the production of antibodies which are specific for native C6, confirming the presence of a C6 epitope on the expressed protein. However, analysis of the intron-exon boundaries of a corresponding genomic clone revealed that the expression clone is in antisense orientation, and is therefore not C6 cDNA. Comparison of the sequences of the expression clone and expressed protein with those for C6 have not demonstrated any significant sequence homology. It is therefore apparent that what has been cloned is a mimotope for C6 which includes in its continuous sequence an epitope that is conformational in C6 and not represented as a continuous sequence in the C6 molecule. Although this was not the purpose of the investigation, these results confirm that screening random expression libraries with antibodies may be an alternative to the synthetic peptide approach to obtain mimotopes reacting with particular antibodies.
已分离并测序了一个指导与抗C6抗体反应的融合蛋白表达的cDNA克隆。与所表达蛋白的14个C末端残基相对应的合成肽引发了针对天然C6的特异性抗体的产生，证实了所表达蛋白上存在C6表位。然而，对相应基因组克隆的内含子-外显子边界的分析表明，表达克隆处于反义方向，因此不是C6 cDNA。将表达克隆和所表达蛋白的序列与C6的序列进行比较，未发现任何显著的序列同源性。因此很明显，所克隆的是C6的模拟表位，其连续序列中包含一个在C6中为构象性且在C6分子中不表示为连续序列的表位。尽管这并非研究目的，但这些结果证实，用抗体筛选随机表达文库可能是获得与特定抗体反应的模拟表位的合成肽方法的替代方法。
