Randall Centre for Cell and Molecular Biophysics, King's College London, London, SE1 1UL, UK.
British Heart Foundation Centre of Research Excellence, King's College London, London, SE1 1UL, UK.
Sci Rep. 2023 Mar 30;13(1):5216. doi: 10.1038/s41598-023-32476-w.
The large unmet demand for new heart failure therapeutics is widely acknowledged. Over the last decades the contractile myofilaments themselves have emerged as an attractive target for the development of new therapeutics for both systolic and diastolic heart failure. However, the clinical use of myofilament-directed drugs has been limited, and further progress has been hampered by incomplete understanding of myofilament function on the molecular level and screening technologies for small molecules that accurately reproduce this function in vitro. In this study we have designed, validated and characterized new high throughput screening platforms for small molecule effectors targeting the interactions between the troponin C and troponin I subunits of the cardiac troponin complex. Fluorescence polarization-based assays were used to screen commercially available compound libraries, and hits were validated using secondary screens and orthogonal assays. Hit compound-troponin interactions were characterized using isothermal titration calorimetry and NMR spectroscopy. We identified NS5806 as novel calcium sensitizer that stabilizes active troponin. In good agreement, NS5806 greatly increased the calcium sensitivity and maximal isometric force of demembranated human donor myocardium. Our results suggest that sarcomeric protein-directed screening platforms are suitable for the development of compounds that modulate cardiac myofilament function.
人们普遍认识到，治疗心力衰竭的新疗法存在巨大的未满足需求。在过去几十年中，收缩性肌丝本身已成为开发治疗收缩性和舒张性心力衰竭新疗法的有吸引力的靶点。然而，肌丝靶向药物的临床应用受到限制，由于对肌丝功能在分子水平上的不完全了解以及用于体外准确再现这种功能的小分子筛选技术，进一步的进展受到了阻碍。在这项研究中，我们设计、验证和表征了针对心脏肌钙蛋白复合物中肌钙蛋白 C 和肌钙蛋白 I 亚基相互作用的新型小分子效应物的高通量筛选平台。使用荧光偏振测定法筛选市售的化合物文库，并使用二次筛选和正交测定法验证命中物。使用等温滴定量热法和 NMR 光谱法表征命中化合物与肌钙蛋白的相互作用。我们确定 NS5806 是一种新型的钙敏化剂，可稳定活性肌钙蛋白。一致的是，NS5806 极大地增加了去垢剂处理的人供体心肌的钙敏感性和最大等长力。我们的结果表明，肌节蛋白靶向筛选平台适合开发调节心肌肌丝功能的化合物。
