Institute of Chemical Sciences and Engineering, Ecole Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland.
J Am Chem Soc. 2013 May 1;135(17):6562-9. doi: 10.1021/ja400461h. Epub 2013 Apr 17.
Bicyclic peptide ligands were found to have good binding affinity and target specificity. However, the method applied to generate bicyclic ligands based on phage-peptide alkylation is technically complex and limits its application to specialized laboratories. Herein, we report a method that involves a simpler and more robust procedure that additionally allows screening of structurally more diverse bicyclic peptide libraries. In brief, phage-encoded combinatorial peptide libraries of the format X(m)CX(n)CX(o)CX(p) are oxidized to connect two pairs of cysteines (C). This allows the generation of 3 × (m + n + o + p) different peptide topologies because the fourth cysteine can appear in any of the (m + n + o + p) randomized amino acid positions (X). Panning of such libraries enriched strongly peptides with four cysteines and yielded tight binders to protein targets. X-ray structure analysis revealed an important structural role of the disulfide bridges. In summary, the presented approach offers facile access to bicyclic peptide ligands with good binding affinities.
双环肽配体具有良好的结合亲和力和靶向特异性。然而，基于噬菌体肽烷基化生成双环配体的方法技术复杂，限制了其在专门实验室的应用。在此，我们报告了一种方法，该方法涉及更简单、更稳健的程序，此外还允许筛选结构更多样化的双环肽文库。简而言之，采用 X(m)CX(n)CX(o)CX(p) 格式的噬菌体编码组合肽文库被氧化以连接两对半胱氨酸 (C)。这允许生成 3×(m+n+o+p)种不同的肽拓扑结构，因为第四个半胱氨酸可以出现在(m+n+o+p)个随机氨基酸位置(X)中的任何一个位置。对这类文库进行淘选强烈富集了具有四个半胱氨酸的肽，并产生了与蛋白质靶标紧密结合的配体。X 射线结构分析揭示了二硫键的重要结构作用。总之，所提出的方法提供了一种获得具有良好结合亲和力的双环肽配体的简便方法。
