Department of Biomolecular Engineering, Graduate School of Engineering, Nagoya University, Nagoya, 464-8603, Japan.
Department of Applied Biosciences, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, 464-8601, Japan.
Biochem Biophys Res Commun. 2021 Apr 23;550:177-183. doi: 10.1016/j.bbrc.2021.02.142. Epub 2021 Mar 9.
Free fatty acid receptor 1 (FFAR1 or GPR40) has attracted attention for the treatment of type 2 diabetes mellitus, and various small-molecule agonists have been developed. However, most FFAR1 agonists as well as endogenous ligands, such as linoleic acids, have high lipophilicity, and their high lipophilicity is related to off-target toxicity. Therefore, we need to focus on new ligand candidates with less toxicity. In this study, we screened peptides with FFAR1 agonist activity as new ligand candidates. First, we used phage display to identify peptides with high affinity to FFAR1. Next, the agonist activities of peptides determined by the phage display were evaluated by the TGF-α shedding assay. Finally, to improve the FFAR1 agonist activity of the peptide, we performed an inclusive single amino acid substitution and sequence analysis. Logistic regression (LR) analysis using 120 physiochemical properties was performed to predict peptides with high FFAR1 agonist activity. STTGTQY determined by phage display promoted glucose-stimulated insulin secretion in pancreatic MIN6 cells. Furthermore, STKGTF predicted by the LR analysis showed high insulin secretion at low concentrations compared to STTGTQY. The results of this study suggest that peptides could be new candidates as FFAR1 agonists.
游离脂肪酸受体 1（FFAR1 或 GPR40）因其在治疗 2 型糖尿病方面的作用而受到关注，已经开发出了各种小分子激动剂。然而，大多数 FFAR1 激动剂以及内源性配体（如亚油酸）具有较高的亲脂性，其较高的亲脂性与脱靶毒性有关。因此，我们需要关注具有较低毒性的新配体候选物。在本研究中，我们筛选了具有 FFAR1 激动活性的肽作为新的配体候选物。首先，我们使用噬菌体展示技术来鉴定与 FFAR1 具有高亲和力的肽。然后，通过 TGF-α 脱落测定评估噬菌体展示确定的肽的激动活性。最后，为了提高肽的 FFAR1 激动活性，我们进行了包容性单氨基酸取代和序列分析。使用 120 种物理化学性质进行逻辑回归（LR）分析，以预测具有高 FFAR1 激动活性的肽。噬菌体展示确定的 STTGTQY 促进了胰腺 MIN6 细胞中葡萄糖刺激的胰岛素分泌。此外，LR 分析预测的 STKGTF 与 STTGTQY 相比，在低浓度下表现出较高的胰岛素分泌。本研究的结果表明，肽可能是 FFAR1 激动剂的新候选物。
