Rudikoff S, Pawlita M, Pumphrey J, Mushinski E, Potter M
J Exp Med. 1983 Nov 1;158(5):1385-400. doi: 10.1084/jem.158.5.1385.
A group of eight IgM hybridoma proteins induced with beta(1,6)-D-galactan-containing antigens has been characterized in terms of primary amino acid sequence and idiotype expression. The H chain amino acid sequences reveal very strong homology in the VH segment although several substitutions are seen that suggest the occurrence of somatic mutation in these IgM molecules. Significant sequence variation was observed in CDR-3, the region generated by the D segment, and the two recombination events, VH-D and D-JH. The number of amino acids in this region contributed by the D segment was found to vary from two to six, yet the overall length of CDR-3 was precisely maintained by the addition of amino acids on either side of D during the recombination processes. These additional amino acids are suggested to result from nucleotide addition by repair enzymes. Idiotypic analysis of these proteins, in conjunction with an assessment of the H chain sequences, has permitted an identification of the molecular basis of both cross-reacting and unique idiotypic determinants expressed by these molecules.
一组由含β(1,6)-D-半乳聚糖抗原诱导产生的八种IgM杂交瘤蛋白，已在一级氨基酸序列和独特型表达方面进行了表征。重链氨基酸序列在VH区段显示出很强的同源性，尽管可以看到一些取代，这表明这些IgM分子中发生了体细胞突变。在CDR-3、由D区段产生的区域以及两个重组事件VH-D和D-JH中观察到了显著的序列变异。发现D区段贡献的该区域氨基酸数量从两个到六个不等，但在重组过程中，通过在D两侧添加氨基酸，CDR-3的总长度得以精确维持。这些额外的氨基酸被认为是由修复酶添加核苷酸所致。对这些蛋白的独特型分析，结合重链序列评估，使得能够鉴定这些分子所表达的交叉反应性和独特独特型决定簇的分子基础。
