Departments of Neuroscience (B.X., J.P., D.L.) and Cell and Molecular Biology (S.V., J.Å., H.G.-T.), Biomedical Centre, Uppsala University, Uppsala, Sweden; and Protein and Peptide Chemistry 2 (S.Ø.) and Obesity Research (J.F.P., B.S.W.), Novo Nordisk A/S, Måløv, Denmark.
Departments of Neuroscience (B.X., J.P., D.L.) and Cell and Molecular Biology (S.V., J.Å., H.G.-T.), Biomedical Centre, Uppsala University, Uppsala, Sweden; and Protein and Peptide Chemistry 2 (S.Ø.) and Obesity Research (J.F.P., B.S.W.), Novo Nordisk A/S, Måløv, Denmark
Mol Pharmacol. 2018 Apr;93(4):323-334. doi: 10.1124/mol.117.110627. Epub 2018 Jan 24.
Understanding the agonist-receptor interactions in the neuropeptide Y (NPY)/peptide YY (PYY) signaling system is fundamental for the design of novel modulators of appetite regulation. We report here the results of a multidisciplinary approach to elucidate the binding mode of the native peptide agonist PYY to the human Y receptor, based on computational modeling, peptide chemistry and in vitro pharmacological analyses. The preserved binding orientation proposed for full-length PYY and five analogs, truncated at the amino terminus, explains our pharmacological results where truncations of the N-terminal proline helix showed little effect on peptide affinity. This was followed by receptor mutagenesis to investigate the roles of several receptor positions suggested by the modeling. As a complement, PYY-(3-36) analogs were synthesized with modifications at different positions in the common PYY/NPY C-terminal fragment (TRQRY-amide). The results were assessed and interpreted by molecular dynamics and Free Energy Perturbation (FEP) simulations of selected mutants, providing a detailed map of the interactions of the PYY/NPY C-terminal fragment with the transmembrane cavity of the Y receptor. The amidated C-terminus would be stabilized by polar interactions with Gln288 and Tyr219, while Gln130 contributes to interactions with Q in the peptide and T is close to the tip of TM7 in the receptor. This leaves the core, -helix of the peptide exposed to make potential interactions with the extracellular loops. This model agrees with most experimental data available for the Y system and can be used as a basis for optimization of Y receptor agonists.
了解神经肽 Y（NPY）/肽 YY（PYY）信号系统中的激动剂-受体相互作用对于设计新型食欲调节调节剂至关重要。我们在此报告了一种多学科方法的结果，该方法基于计算建模、肽化学和体外药理学分析，阐明了天然肽激动剂 PYY 与人 Y 受体结合的模式。提出的全长 PYY 和五个截短 N 端脯氨酸螺旋的类似物的保留结合取向解释了我们的药理学结果，其中 N 端脯氨酸螺旋的截短对肽亲和力几乎没有影响。随后进行了受体突变以研究建模提出的几个受体位置的作用。作为补充，用不同位置的修饰合成了 PYY-（3-36）类似物在共同的 PYY/NPY C 端片段（TRQRY-酰胺）中。结果通过对选定突变体的分子动力学和自由能扰动（FEP）模拟进行评估和解释，提供了 PYY/NPY C 端片段与 Y 受体跨膜腔相互作用的详细图谱。酰胺化的 C 端通过与 Gln288 和 Tyr219 的极性相互作用得到稳定，而 Gln130 有助于与肽中的 Q 相互作用，而 T 靠近受体 TM7 的尖端。这使得肽的核心，-螺旋暴露在外，以与细胞外环形成潜在的相互作用。该模型与 Y 系统中大多数现有实验数据一致，可作为优化 Y 受体激动剂的基础。
