Center of Structural and Cell Biology in Medicine, Institute of Chemistry and Metabolomics, University of Lübeck, Ratzeburger Allee 160, 23562 Lübeck, Germany.
Center of Structural and Cell Biology in Medicine, Institute of Biochemistry, University of Lübeck, Ratzeburger Allee 160, 23562 Lübeck, Germany.
J Am Chem Soc. 2022 Jul 27;144(29):13060-13065. doi: 10.1021/jacs.2c05603. Epub 2022 Jul 13.
We have used chemical shift perturbation (CSP) and saturation transfer difference (STD) NMR experiments to identify and characterize the binding of selected ligands to the receptor-binding domain (RBD) of the spike glycoprotein (S-protein) of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). We also subjected full-length S-protein to STD NMR experiments, allowing correlations with RBD-based results. CSPs reveal the binding sites for heparin and fondaparinux, and affinities were measured using CSP titrations. We then show that α-2,3-sialyllactose binds to the S-protein but not to the RBD. Finally, combined CSP and STD NMR experiments show that lifitegrast, a compound used for the treatment of dry eye, binds to the linoleic acid (LA) binding pocket with a dissociation constant in the μM range. This is an interesting finding, as lifitegrast lends itself well as a blueprint for medicinal chemistry, eventually furnishing novel entry inhibitors targeting the highly conserved LA binding site.
我们使用化学位移扰动（CSP）和饱和转移差异（STD）NMR 实验来鉴定和表征选定配体与严重急性呼吸综合征冠状病毒 2（SARS-CoV-2）的刺突糖蛋白（S-蛋白）的受体结合域（RBD）的结合。我们还对全长 S-蛋白进行了 STD NMR 实验，允许与基于 RBD 的结果进行关联。CSP 揭示了肝素和磺达肝素的结合位点，并通过 CSP 滴定测量了亲和力。然后，我们表明 α-2,3-唾液酸乳糖结合到 S-蛋白上，但不结合到 RBD 上。最后，组合的 CSP 和 STD NMR 实验表明，用于治疗干眼症的化合物利福昔明结合到 linoleic 酸（LA）结合口袋中，解离常数在μM 范围内。这是一个有趣的发现，因为利福昔明本身很适合作为药物化学的蓝图，最终提供针对高度保守的 LA 结合位点的新型进入抑制剂。
