Kinnun Jacob J, Scott Haden L, Ashkar Rana, Katsaras John
Large Scale Structures Group, Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN, United States.
Oak Ridge National Laboratory, Shull-Wollan Center, Oak Ridge, TN, United States.
Front Chem. 2021 Apr 27;9:642851. doi: 10.3389/fchem.2021.642851. eCollection 2021.
Cell membranes and their associated structures are dynamical supramolecular structures where different physiological processes take place. Detailed knowledge of their static and dynamic structures is therefore needed, to better understand membrane biology. The structure-function relationship is a basic tenet in biology and has been pursued using a range of different experimental approaches. In this review, we will discuss one approach, namely the use of neutron scattering techniques as applied, primarily, to model membrane systems composed of lipid bilayers. An advantage of neutron scattering, compared to other scattering techniques, is the differential sensitivity of neutrons to isotopes of hydrogen and, as a result, the relative ease of altering sample contrast by substituting protium for deuterium. This property makes neutrons an ideal probe for the study of hydrogen-rich materials, such as biomembranes. In this review article, we describe isotopic labeling studies of model and viable membranes, and discuss novel applications of neutron contrast variation in order to gain unique insights into the structure, dynamics, and molecular interactions of biological membranes. We specifically focus on how small-angle neutron scattering data is modeled using different contrast data and molecular dynamics simulations. We also briefly discuss neutron reflectometry and present a few recent advances that have taken place in neutron spin echo spectroscopy studies and the unique membrane mechanical data that can be derived from them, primarily due to new models used to fit the data.
细胞膜及其相关结构是动态的超分子结构，不同的生理过程在此发生。因此，需要详细了解其静态和动态结构，以更好地理解膜生物学。结构-功能关系是生物学的一个基本原则，人们一直在使用一系列不同的实验方法来探究这一关系。在本综述中，我们将讨论一种方法，即主要应用于由脂质双层组成的模型膜系统的中子散射技术。与其他散射技术相比，中子散射的一个优势在于中子对氢同位素具有不同的敏感性，因此，通过用氘取代氢来改变样品对比度相对容易。这一特性使中子成为研究富含氢的材料（如生物膜）的理想探针。在这篇综述文章中，我们描述了模型膜和活细胞膜的同位素标记研究，并讨论了中子对比度变化的新应用，以便深入了解生物膜的结构、动力学和分子相互作用。我们特别关注如何使用不同的对比度数据和分子动力学模拟对小角中子散射数据进行建模。我们还简要讨论了中子反射率，并介绍了中子自旋回波光谱研究中最近取得的一些进展，以及主要由于用于拟合数据的新模型而能够从中获得的独特的膜力学数据。
