The intrinsic contributions of tyrosine, serine, glycine and arginine to the affinity and specificity of antibodies
The intrinsic contributions of tyrosine, serine, glycine and arginine to the affinity and specificity of antibodies
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DOI：
10.1016/j.jmb.2008.01.093
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发表时间：
2008-04-11
影响因子：
5.6
通讯作者：
Sidhu, Sachdev S.
中科院分区：
文献类型：
--
作者：
Birtalan, Sara;Zhang, Yingnan;Sidhu, Sachdev S.
使用具有有限化学多样性的合成抗体库来探索四种氨基酸（Tyr、Ser、Gly和Arg）对抗原识别的亲和力和特异性的内在贡献。非特异性结合与抗原结合位点的Tyr、Ser或Gly含量之间没有相关性，事实上，最特异的抗体是Tyr含量最高的抗体。相反，精氨酸含量明显与非特异性结合增加相关。我们将Tyr、Ser和Gly组合以产生具有亚纳摩尔范围内的亲和力的高度特异性合成抗体，表明天然抗体种系序列中Tyr、Ser和Gly的高丰度反映了这些残基一起工作以介导抗原识别的内在能力。尽管是一个主要的功能贡献者共同进化的蛋白质-蛋白质界面，我们发现，精氨酸一般不有助于幼稚抗原结合位点的亲和力，是有害的特异性。同样，这与天然抗体的研究一致，天然抗体的研究表明，非特异性的自反应抗体富含Arg和其他带正电荷的残基。我们的研究结果表明，天真的分子识别的原则不同于那些管理共同进化的相互作用。可以设计类似的研究来探索其他氨基酸在分子识别中的作用。这些研究的结果应该阐明天然蛋白质-蛋白质相互作用的基本原理，并有助于设计功能超出天然蛋白质范围的合成结合蛋白。(C)2008爱思唯尔有限公司版权所有。
Synthetic antibody libraries with restricted chemical diversity were used to explore the intrinsic contributions of four amino acids (Tyr, Ser, Gly and Arg) to the affinity and specificity of antigen recognition. There was no correlation between nonspecific binding and the content of Tyr, Ser or Gly in the antigen-binding site, and in fact, the most specific antibodies were those with the highest Tyr content. In contrast, Arg content was clearly correlated with increased nonspecific binding. We combined Tyr, Ser and Gly to generate highly specific synthetic antibodies with affinities in the sub-nanomolar range, showing that the high abundance of Tyr, Ser and Gly in natural antibody germ line sequences reflects the intrinsic capacity of these residues to work together to mediate antigen recognition. Despite being a major functional contributor to co-evolved protein-protein interfaces, we find that Arg does not contribute generally to the affinity of naive antigen-binding sites and is detrimental to specificity. Again, this is consistent with studies of natural antibodies, which have shown that nonspecific, self-reactive antibodies are rich in Arg and other positively charged residues. Our findings suggest that the principles governing naive molecular recognition differ from those governing co-evolved interactions. Analogous studies can be designed to explore the roles of the other amino acids in molecular recognition. Results of such studies should illuminate the basic principles underlying natural protein-protein interactions and should aid the design of synthetic binding proteins with functions beyond the scope of natural proteins. (C) 2008 Elsevier Ltd. All rights reserved.