State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic and Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240, China.
Laboratory of Molecular Architecture, Media Lab, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA.
Nat Commun. 2024 Jun 10;15(1):4293. doi: 10.1038/s41467-024-48513-9.
Membrane proteins are critical to biological processes and central to life sciences and modern medicine. However, membrane proteins are notoriously challenging to study, mainly owing to difficulties dictated by their highly hydrophobic nature. Previously, we reported QTY code, which is a simple method for designing water-soluble membrane proteins. Here, we apply QTY code to a transmembrane receptor, histidine kinase CpxA, to render it completely water-soluble. The designed CpxA exhibits expected biophysical properties and highly preserved native molecular function, including the activities of (i) autokinase, (ii) phosphotransferase, (iii) phosphatase, and (iv) signaling receptor, involving a water-solubilized transmembrane domain. We probe the principles underlying the balance of structural stability and activity in the water-solubilized transmembrane domain. Computational approaches suggest that an extensive and dynamic hydrogen-bond network introduced by QTY code and its flexibility may play an important role. Our successful functional preservation further substantiates the robustness and comprehensiveness of QTY code.
膜蛋白对于生物过程至关重要，是生命科学和现代医学的核心。然而，由于其高度疏水性的特点，膜蛋白的研究极具挑战性。此前，我们报道了 QTY 编码，这是一种设计水溶性膜蛋白的简单方法。在这里，我们将 QTY 编码应用于跨膜受体组氨酸激酶 CpxA，使其完全水溶性。设计的 CpxA 表现出预期的生物物理特性和高度保留的天然分子功能，包括（i）自激酶、（ii）磷酸转移酶、（iii）磷酸酶和（iv）信号受体的活性，涉及水溶性跨膜结构域。我们探究了水溶性跨膜结构域中结构稳定性和活性平衡的原理。计算方法表明，由 QTY 编码引入的广泛而动态的氢键网络及其灵活性可能发挥重要作用。我们成功地保留了功能，进一步证实了 QTY 编码的稳健性和全面性。
