Abstract：
Lipid biosensors are molecular tools used both in vivo and in vitro applications, capable of selectively detecting specific types of lipids in biological membranes. However, despite their extensive use, there is a lack of systematic characterization of their binding properties in various membrane conditions. The purpose of this study was to investigate the impact of membrane properties, such as fluidity and membrane charge, on the sensitivity of two lipid biosensors, LactC2 and P4M, to their target lipids, phosphatidylserine (PS) or phosphatidylinositol 4-phosphate (PI4P), respectively. Dual-color fluorescence cross-correlation spectroscopy, employed in this study, provided a useful technique to investigate interactions of these recombinant fluorescent biosensors with liposomes of varying compositions. The results of the study demonstrate that the binding of the LactC2 biosensor to low levels of PS in the membrane is highly supported by the presence of anionic lipids or membrane fluidity. However, at high PS levels, the presence of anionic lipids does not further enhance binding of LactC2. In contrast, neither membrane charge, nor membrane fluidity significantly affect the binding affinity of P4M to PI4P. These findings provide valuable insights into the role of membrane properties on the binding properties of lipid biosensors.
摘要：
脂质生物传感器是体内和体外应用的分子工具，能够选择性地检测生物膜中特定类型的脂质。然而,尽管它们被广泛使用，它们在各种膜条件下的结合特性缺乏系统的表征。这项研究的目的是研究膜性能的影响，如流动性和膜电荷，关于两种脂质生物传感器的灵敏度，LactC2和P4M，它们的目标脂质，磷脂酰丝氨酸（PS）或磷脂酰肌醇4-磷酸（PI4P），分别。双色荧光互相关光谱,受雇于这项研究，提供了一种有用的技术来研究这些重组荧光生物传感器与不同组成的脂质体的相互作用。研究结果表明，阴离子脂质的存在或膜流动性高度支持了LactC2生物传感器与膜中低水平PS的结合。然而,在高PS水平下，阴离子脂质的存在不会进一步增强LactC2的结合。相比之下,既没有膜电荷，膜流动性也显着影响P4M与PI4P的结合亲和力。这些发现为膜特性对脂质生物传感器的结合特性的作用提供了有价值的见解。
