Peptides are promising scaffolds for use as therapeutics, targeting interactions previously considered to be “undruggable” by small molecules. While short peptides are generally unstructured in solution and rapidly degraded by proteases in the cell cytosol, peptide stapling offers an effective method to both stabilize peptides in a helical structure and increase resistance to proteolytic degradation. Most studies of peptide stapling have focused on residues with i, i + 4 and i, i + 7 spacing, while stapling of residues with i, i + 3 spacing has been understudied. Herein, we evaluated a suite of bifunctional linkers for stapling between residues with i, i + 3 spacing, comparing the ability of each compound to react with the peptide and the degree of helicity conferred. Finally, we evaluated the ability of the stapling to increase proteolytic resistance in cell lysates, comparing stapling of i, i + 3 and i, i + 4 spacing, with i, i + 3 spacing resulting in a greater increase in peptide half-life in the model system. This presents an effective stapling strategy, adding to the peptide stapling toolbox.

肽是有前途的支架，可用于治疗，靶向以前被小分子认为“不可吸收”的相互作用。虽然短肽通常在溶液中是非结构化的，并且会被细胞质溶胶中的蛋白酶迅速降解，但肽钉钉合提供了一种有效的方法，既可以将肽稳定在螺旋结构中，又可以增加对蛋白水解降解的抵抗力。肽装订的大多数研究都集中在i，i + 4和i，i + 7间距的残基上，而i，i + 3间距的残基的装订还没有得到充分研究。本文中，我们评估了一套双功能接头，用于在i，i + 3间距的残基之间进行装订，比较了每种化合物与肽反应的能力和所赋予的螺旋度。最后，我们比较了i，i + 3和i，i + 4间距的钉合与i，i + 3间距的钉合导致肽半衰期更长的增加，从而评估了钉合增加细胞裂解液中蛋白水解抗性的能力。模型系统。这提供了一种有效的装订策略，并添加到了肽装订工具箱中。