Jaton J C, Riesen W
Ann Immunol (Paris). 1976 Jun-Jul;127(3-4):273-83.
The amino acid sequences of the V domains (VL + VH regions) of 3 antibodies raised to type III pneumococcal polysaccharide in individual outbred rabbits are reported. With the exception of the second hypervariable section of the L chains, these antibodies have very different sequences in the hypervariable segments of the V domains. Within the third hypervariable region of the H chain, each antibody has a different length. On the sole basis of the amino acid sequences of these three anti-pneumococcal antibodies, the results do not support the concept of a simple correlation between primary structure in the hypervariable sections (known to determine the shape of the combining site) and antigen-binding specificity. In view of the large number of amino acid interchanges in the hypervariable positions and because of the size difference between the rabbit H chains, it is likely that each anti-SIII H chain studied here represents the product of a different structural germ line gene. In contrast to such a complex immune response to a relatively simple polysaccharide antigen, an extensive structural uniformity has been observed in the heavy chains of mouse myeloma proteins with phosphorylcholine activity and a mu chain from a human Waldenström IgM endowed with the same activity. The finding of a very similar heavy chain variable region in two different species which are separated by about 75 million years in evolution favours the concept of stable transmission of variable region genes throughout evolution.
报道了在个体远交兔中产生的3种针对Ⅲ型肺炎球菌多糖的抗体V结构域（VL + VH区域）的氨基酸序列。除轻链的第二个高变区外，这些抗体在V结构域的高变区具有非常不同的序列。在重链的第三个高变区内，每种抗体的长度都不同。仅基于这三种抗肺炎球菌抗体的氨基酸序列，结果不支持高变区的一级结构（已知可决定结合位点的形状）与抗原结合特异性之间存在简单相关性的概念。鉴于高变位置存在大量氨基酸互换，且由于兔重链之间存在大小差异，这里研究的每种抗SIII重链可能代表不同结构种系基因的产物。与对相对简单的多糖抗原的这种复杂免疫反应形成对比的是，在具有磷酸胆碱活性的小鼠骨髓瘤蛋白的重链以及来自具有相同活性的人类瓦尔登斯特伦IgM的μ链中观察到广泛的结构一致性。在进化上相隔约7500万年的两个不同物种中发现非常相似的重链可变区，这支持了可变区基因在整个进化过程中稳定传递的概念。
