Hojo Keiko, Hossain Mohammed Akhter, Tailhades Julien, Shabanpoor Fazel, Wong Lilian L L, Ong-Pålsson Emma E K, Kastman Hanna E, Ma Sherie, Gundlach Andrew L, Rosengren K Johan, Wade John D, Bathgate Ross A D
Faculty of Pharmaceutical Sciences and Cooperative Research Center of Life Sciences, Kobe Gakuin University , Chuo-ku, Kobe 650-8586, Japan.
Florey Institute of Neuroscience and Mental Health and Florey Department of Neuroscience and Mental Health, University of Melbourne , Melbourne, Victoria 3052, Australia.
J Med Chem. 2016 Aug 25;59(16):7445-56. doi: 10.1021/acs.jmedchem.6b00265. Epub 2016 Aug 8.
Structure-activity studies of the insulin superfamily member, relaxin-3, have shown that its G protein-coupled receptor (RXFP3) binding site is contained within its central B-chain α-helix and this helical structure is essential for receptor activation. We sought to develop a single B-chain mimetic that retained agonist activity. This was achieved by use of solid phase peptide synthesis together with on-resin ruthenium-catalyzed ring closure metathesis of a pair of judiciously placed i,i+4 α-methyl, α-alkenyl amino acids. The resulting hydrocarbon stapled peptide was shown by solution NMR spectroscopy to mimic the native helical conformation of relaxin-3 and to possess potent RXFP3 receptor binding and activation. Alternative stapling procedures were unsuccessful, highlighting the critical need to carefully consider both the peptide sequence and stapling methodology for optimal outcomes. Our result is the first successful minimization of an insulin-like peptide to a single-chain α-helical peptide agonist which will facilitate study of the function of relaxin-3.
胰岛素超家族成员松弛素-3的构效关系研究表明，其G蛋白偶联受体（RXFP3）结合位点位于其中心B链α螺旋内，且这种螺旋结构对于受体激活至关重要。我们试图开发一种保留激动剂活性的单B链模拟物。这是通过使用固相肽合成以及一对精心放置的i,i+4α-甲基、α-烯基氨基酸的树脂上钌催化闭环复分解反应来实现的。溶液核磁共振光谱显示，所得的烃类订书肽模拟了松弛素-3的天然螺旋构象，并具有强大的RXFP3受体结合和激活能力。其他订书方法均未成功，这突出表明为了获得最佳结果，必须仔细考虑肽序列和订书方法。我们的结果是首次成功地将胰岛素样肽最小化为单链α螺旋肽激动剂，这将有助于对松弛素-3的功能进行研究。
