ISIS Pulsed Neutron and Muon Source, Science and Technology Facilities Council, Rutherford Appleton Laboratory, Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 OQX, U.K.
Biochem Soc Trans. 2021 Aug 27;49(4):1537-1546. doi: 10.1042/BST20201071.
Neutron reflectometry (NR) is a large-facility technique used to examine structure at interfaces. In this brief review an introduction to the utilisation of NR in the study of protein-lipid interactions is given. Cold neutron beams penetrate matter deeply, have low energies, wavelengths in the Ångstrom regime and are sensitive to light elements. High differential hydrogen sensitivity (between protium and deuterium) enables solution and sample isotopic labelling to be utilised to enhance or diminish the scattering signal of individual components within complex biological structures. The combination of these effects means NR can probe buried structures such as those at the solid-liquid interface and encode molecular level structural information on interfacial protein-lipid complexes revealing the relative distribution of components as well as the overall structure. Model biological membrane sample systems can be structurally probed to examine phenomena such as antimicrobial mode of activity, as well as structural and mechanistic properties peripheral/integral proteins within membrane complexes. Here, the example of the antimicrobial protein α1-purothionin binding to a model Gram negative bacterial outer membrane is used to highlight the utilisation of this technique, detailing how changes in the protein/lipid distributions across the membrane before and after the protein interaction can be easily encoded using hydrogen isotope labelling.
中子反射率（NR）是一种大型设施技术，用于研究界面处的结构。在这篇简要综述中，介绍了 NR 在研究蛋白质-脂质相互作用中的应用。冷中子束能够深入穿透物质，能量低，波长在埃范围内，对轻元素敏感。高的氘氕差分氢灵敏度使得溶液和样品同位素标记得以利用，以增强或减弱复杂生物结构中各个成分的散射信号。这些效应的结合意味着 NR 可以探测埋藏的结构，如固-液界面的结构，并对界面蛋白质-脂质复合物进行分子水平的结构信息编码，揭示各成分的相对分布以及整体结构。可以对模型生物膜样品系统进行结构探测，以研究抗菌作用模式等现象，以及膜复合物中周边/整合蛋白的结构和力学特性。本文以抗菌蛋白α1-短杆菌肽素与模型革兰氏阴性细菌外膜的结合为例，突出了该技术的应用，详细说明了如何使用氢同位素标记轻松编码蛋白质/脂质在膜相互作用前后在膜中分布的变化。
