Centre National de la Recherche Scientifique, University of Strasbourg, CAMB UMR 7199, Strasbourg, France.
Channel-Receptors Unit, Institut Pasteur, UMR 3571, Paris, France.
Methods Mol Biol. 2022;2510:239-252. doi: 10.1007/978-1-0716-2384-8_12.
P2X7 receptors are ATP-gated ion channels permeable to metal cations, such as Na, K, and Ca. They also exhibit permeability to various large molecular weight species, reaching up to 900 Da, in a process known as macropore formation, which is a unique functional hallmark across the P2X family. While well-documented in a range of different cell types, the molecular mechanism underlying this phenomenon is poorly understood, and has been clouded through the use of electrophysiological methodology prone to artifacts as a result of significant changes in ionic concentrations in asymmetric conditions. In this chapter, we discuss the permeation properties of P2X7, the related methodological challenges and the use of symmetrical organic cation solutions as a useful technique for probing P2X7 permeation.
P2X7 受体是一种 ATP 门控离子通道，对金属阳离子（如 Na、K 和 Ca）具有通透性。它们还表现出对各种大分子物质的通透性，最大可达 900 Da，这一过程称为大孔形成，是 P2X 家族的独特功能标志。尽管在多种不同的细胞类型中都有很好的记录，但这种现象背后的分子机制还不太清楚，并且由于不对称条件下离子浓度的显著变化，容易产生电生理学方法的假象，这使得该机制更加复杂。在本章中，我们将讨论 P2X7 的渗透性、相关的方法学挑战以及使用对称有机阳离子溶液作为探测 P2X7 渗透性的有用技术。
