Lösche M, Piepenstock M, Diederich A, Grünewald T, Kjaer K, Vaknin D
Institute of Physical Chemistry, Johannes-Gutenberg-Universität Mainz, Germany.
Biophys J. 1993 Nov;65(5):2160-77. doi: 10.1016/S0006-3495(93)81269-4.
The molecular organization of streptavidin (SA) bound to aqueous surface monolayers of biotin-functionalized lipids and binary lipid mixtures has been investigated with neutron reflectivity and electron and fluorescence microscopy. The substitution of deuterons (2H) for protons (1H), both in subphase water molecules and in the alkyl chains of the lipid surface monolayer, was utilized to determine the interface structure on the molecular length scale. In all cases studied, the protein forms monomolecular layers underneath the interface with thickness values of approximately 40 A. A systematic dependence of the structural properties of such self-assembled SA monolayers on the surface chemistry was observed: the lateral protein density depends on the length of the spacer connecting the biotin moiety and its hydrophobic anchor. The hydration of the lipid head groups in the protein-bound state depends on the dipole moment density at the interface.
利用中子反射率、电子显微镜和荧光显微镜研究了与生物素功能化脂质和二元脂质混合物的水相表面单层结合的链霉亲和素（SA）的分子组织。通过用氘核（2H）取代亚相水分子和脂质表面单层烷基链中的质子（1H），来确定分子长度尺度上的界面结构。在所研究的所有情况下，蛋白质在界面下方形成单分子层，厚度约为40埃。观察到这种自组装SA单分子层的结构性质对表面化学有系统依赖性：横向蛋白质密度取决于连接生物素部分及其疏水锚定基团的间隔物的长度。蛋白质结合状态下脂质头部基团的水合作用取决于界面处的偶极矩密度。
