School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, UK; School of Biochemistry, University of Bristol, University Walk, Bristol BS8 1TD, UK.
Randall Centre of Cell and Molecular Biophysics, King's College London, London, SE1 1UL, UK.
Cell Chem Biol. 2021 Sep 16;28(9):1347-1355.e5. doi: 10.1016/j.chembiol.2021.03.010. Epub 2021 Apr 9.
Synthetic peptides are attractive candidates to manipulate protein-protein interactions inside the cell as they mimic natural interactions to compete for binding. However, protein-peptide interactions are often dynamic and weak. A challenge is to design peptides that make improved interactions with the target. Here, we devise a fragment-linking strategy-"mash-up" design-to deliver a high-affinity ligand, KinTag, for the kinesin-1 motor. Using structural insights from natural micromolar-affinity cargo-adaptor ligands, we have identified and combined key binding features in a single, high-affinity ligand. An X-ray crystal structure demonstrates interactions as designed and reveals only a modest increase in interface area. Moreover, when genetically encoded, KinTag promotes transport of lysosomes with higher efficiency than natural sequences, revealing a direct link between motor-adaptor binding affinity and organelle transport. Together, these data demonstrate a fragment-linking strategy for peptide design and its application in a synthetic motor ligand to direct cellular cargo transport.
合成肽是一种有吸引力的候选物，可以在细胞内操纵蛋白质-蛋白质相互作用，因为它们模拟自然相互作用以竞争结合。然而，蛋白质-肽相互作用通常是动态的和弱的。一个挑战是设计能够改善与靶标相互作用的肽。在这里，我们设计了一种片段连接策略 - “混搭”设计 - 来提供高亲和力的配体 KinTag，用于驱动蛋白-1 马达。利用来自天然微摩尔亲和力货物衔接配体的结构见解，我们在单个高亲和力配体中鉴定并组合了关键结合特征。X 射线晶体结构证明了按设计进行的相互作用，并仅显示界面面积略有增加。此外，当基因编码时，KinTag 以比天然序列更高的效率促进溶酶体的运输，揭示了马达-衔接物结合亲和力与细胞器运输之间的直接联系。总之，这些数据证明了一种用于肽设计的片段连接策略及其在指导细胞货物运输的合成马达配体中的应用。
