Cardiolipin binding a light chain from lupus-prone mice.
Cardiolipin binding a light chain from lupus-prone mice.
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心磷脂与易患狼疮的小鼠的轻链结合。
DOI：
10.1021/bi972277q
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发表时间：
1998
期刊：
影响因子：
--
通讯作者：
Thiagarajan,P
中科院分区：
文献类型：
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作者：
Pereira,B;Benedict,CR;Le,A;Shapiro,SS;Thiagarajan,P
系统性红斑狼疮中的自身抗体与高度保守分子如核酸、细胞骨架蛋白、磷脂和磷脂结合蛋白上的多个表位反应。重链和轻链可变序列（VH和VL）的分析表明，一组有限的V基因产生这些自身抗体。从狼疮易感小鼠品系（F1雄性NZW × BXSB）中制备了几种单克隆抗体。这些抗体中的两个，A1.72和A1.84，直接与心磷脂反应，并分析其VH和VL序列。令人惊讶的是，这两种抗体具有相同的轻链可变序列，尽管具有基本上不同的重链可变序列。该VL序列VL 72/84与仅具有四个单核苷酸取代的种系序列具有97%的同一性。当该VL序列与其他单克隆抗体的VH序列改组并在earth ichiacoli中表达为单链可变片段（scFv）时，其赋予杂交体心磷脂结合活性。此外，VL 72/84序列在没有任何VH序列的情况下单独表达时也结合心磷脂。将抗体及其重组片段在心磷脂脂质体上进行免疫亲和纯化。心磷脂轻链的解离常数与完整分子相似（21 ± 0.01 vs 20 ± 0.03 nM）。这些研究表明，在不存在任何其他免疫球蛋白结构域的情况下，单独的VL序列可以介导心磷脂结合，从而提高了某些抗体的抗原特异性可能仅存在于其轻链序列中的可能性。
Autoantibodies in systemic lupus erythematosus react with multiple epitopes on highly conserved molecules such as nucleic acids, cytoskeletal proteins, phospholipids, and phospholipid-binding proteins. Analysis of the heavy- and light-chain variable sequences (VH and VL) has shown that a restricted set of V genes gives rise to these autoantibodies. Several monoclonal antibodies were developed from a strain of mouse prone to lupus (F1 male NZW × BXSB). Two of these antibodies, A1.72 and A1.84, reacted directly with cardiolipin and their VH and VL sequences were analyzed. Surprisingly, these two antibodies had identical light-chain variable sequences despite having substantially different heavy-chain variable sequences. This VL sequence, VL 72/84 was 97% identical with the germ-line sequences with only four single nucleotide substitutions. When this VL sequence was shuffled with the VH sequence of other monoclonal antibodies and expressed as single chain variable fragment (scFv) inEscherichiacoli, it imparted cardiolipin-binding activity to the hybrids. Furthermore, the VL 72/84 sequence, when expressed alone without any VH sequence, also bound to cardiolipin. The antibodies and their recombinant fragments were immunoaffinity-purified on cardiolipin liposomes. The dissociation constant of the light chain for cardiolipin was similar to the intact molecule (21 ± 0.01 vs 20 ± 0.03 nM). These studies demonstrate that the VL sequence alone, in the absence of any other immunoglobulin domains, can mediate cardiolipin binding, raising the possibility that antigen specificity of certain antibodies may exclusively reside in their light-chain sequences.