英国牛津大学Robinson Carol V.团队不是了在天然细胞信号环境中定义药物靶向的蛋白形式特异性相互作用。相关研究成果发表在2025年1月13日出版的国际学术期刊《自然—化学》上。

了解天然脂质双层内膜蛋白-配体相互作用的动力学是药物发现的主要目标。通常使用基于细胞的检测，然而，它们往往对蛋白质修饰的影响视而不见。

该文中，研究人员使用原型G蛋白偶联受体视紫红质为研究对象，发现受体及其效应器可以通过质谱仪中的红外照射，直接从视网膜杆盘膜释放。随后通过红外多光子解离进行分离和解离，实现了对单个视网膜蛋白形态的测序。具体来说，研究人员对视紫红质的不同蛋白型、局部不稳定的棕榈酰化进行了分类，发现了一种消除膜结合的Gβγ蛋白型，并定义了影响其组装的G蛋白的脂质修饰。

鉴于涉及视力的不良副作用的报告，研究人员描述了两种磷酸二酯酶5抑制剂伐地那非和西地那非，与视网膜杆磷酸二酯酶6（PDE6）的脱靶药物结合。结果表明，PDE6具有不同的脱靶反应性，并且对G蛋白的脂化蛋白形式具有相互作用偏好。

总之，该研究强调了在天然膜环境中探测蛋白质-配体相互作用的机会。

附：英文原文

Title: Defining proteoform-specific interactions for drug targeting in a native cell signalling environment

Author: Lutomski, Corinne A., Bennett, Jack L., El-Baba, Tarick J., Wu, Di, Hinkle, Joshua D., Burnap, Sean A., Liko, Idlir, Mullen, Christopher, Syka, John E. P., Struwe, Weston B., Robinson, Carol V.

Issue&Volume: 2025-01-13

Abstract: Understanding the dynamics of membrane protein–ligand interactions within a native lipid bilayer is a major goal for drug discovery. Typically, cell-based assays are used, however, they are often blind to the effects of protein modifications. In this study, using the archetypal G protein-coupled receptor rhodopsin, we found that the receptor and its effectors can be released directly from retina rod disc membranes using infrared irradiation in a mass spectrometer. Subsequent isolation and dissociation by infrared multiphoton dissociation enabled the sequencing of individual retina proteoforms. Specifically, we categorized distinct proteoforms of rhodopsin, localized labile palmitoylations, discovered a Gβγ proteoform that abolishes membrane association and defined lipid modifications on G proteins that influence their assembly. Given reports of undesirable side-effects involving vision, we characterized the off-target drug binding of two phosphodiesterase 5 inhibitors, vardenafil and sildenafil, to the retina rod phosphodiesterase 6 (PDE6). The results demonstrate differential off-target reactivity with PDE6 and an interaction preference for lipidated proteoforms of G proteins. In summary, this study highlights the opportunities for probing proteoform–ligand interactions within natural membrane environments.

DOI: 10.1038/s41557-024-01711-w

Source: https://www.nature.com/articles/s41557-024-01711-w