Diversity at the variable-joining region boundary of lambda light chains has a pronounced effect on immunoglobulin ligand-binding activity.
Diversity at the variable-joining region boundary of lambda light chains has a pronounced effect on immunoglobulin ligand-binding activity.
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lambda 轻链可变连接区边界的多样性对免疫球蛋白配体结合活性具有显着影响。
DOI：
10.1073/pnas.81.19.6139
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发表时间：
1984
影响因子：
11.1
通讯作者：
Eisen,HN
中科院分区：
文献类型：
--
作者：
Azuma,T;Igras,V;Reilly,EB;Eisen,HN
通过将具有已知可变区(V)氨基酸或核苷酸序列的轻链(L)与骨髓瘤蛋白或单抗的重链(H)链重组，我们获得了重组的IGs，它们在已知的L链位上只有一个或几个氨基酸替换。重组免疫球蛋白与2，4-二硝基苯基(DNP)配体亲和力的差异表明，在λ链的V-J边界，氨基酸的免疫球蛋白结合活性有显著的影响。在一个例子中，两个重组的IGs对epsilon-DNP-氨基己酸酯的亲和力相差约1000倍，在一级结构上的不同之处在于它们的lambda 2链的V-J接头(第98位)只有一个酪氨酸-苯丙氨酸取代--即大约660个氨基酸残基(L+H链)中的一个。通过关注亲和力的变化，鉴定了具有异常V lambda-J lambda连接残基的链。由于基因片段组装引起的连接氨基酸变异(V/J或V/D/J)对三级结构有重要影响，因此可能是抗体配体结合多样性的重要来源。
By recombining lambda light (L) chains having known variable (V) region amino acid or nucleotide sequences with a heavy (H) chain from a myeloma protein or a monoclonal antibody, we obtained reconstituted Igs that differed from each other in sequence by only one or a few amino acid substitutions at known L chain positions. Differences in affinity of the reconstituted Igs for 2,4-dinitrophenyl (DNP) ligands revealed a pronounced effect on Ig binding activity of amino acids at the V-J boundary of the lambda chains. In one instance, two reconstituted Igs that differed about 1000-fold in affinity for epsilon-DNP-aminocaproate differed in primary structure by only a single tyrosine-phenylalanine substitution at the V-J junction (position 98) of their lambda 2 chains--i.e., by only one out of approximately 660 amino acid residues (L + H chains). By focusing on affinity changes, chains with unusual V lambda-J lambda junctional residues were identified. It is possible that because of a critical effect on tertiary structure junctional amino acid variations arising from gene segment assembly (V/J and perhaps V/D/J) constitute an important source of ligand-binding diversity of antibodies.