Sui S F, Liu Z, Li W, Xiao C, Wang S, Gao Q, Zhou Q
State Key Laboratory of Biomembrane and Membrane Biotechnology, Department of Biological Sciences and Biotechnology, Tsinghua University, Beijing, China.
FEBS Lett. 1996 Jun 17;388(2-3):103-11. doi: 10.1016/0014-5793(96)00528-5.
Two-dimensional (2D) crystals of rabbit C-reactive protein (CRP) have been obtained by protein binding on lipid monolayers at the air/water interface. Two different types of crystalline arrays of CRP were obtained, by specific binding and non-specific adsorption to the lipids. Electron crystallographic analysis of the negatively stained specimens showed that the unit cell parameters of the CRP 2D crystals formed by specific binding were a=81 angstroms, b=78 angstroms, gamma=118.35 degrees, and those formed by nonspecific adsorption were a=74 angstroms, b=67 angstroms, gamma=95.5 degrees, both with the layer group p1. Projection maps were obtained at a resolution of 26 angstroms and 22 angstroms respectively. They showed that only the monomers of the CRP were packed in the 2D arrays and the orientations of the monomers on the lipid monolayers were different in the two types of crystals. By comparing the two projection maps, a preliminary shape of the CRP monomer has been derived. A model of the pentameric structure of the oligomeric CRP has been proposed.
通过在空气/水界面的脂质单层上进行蛋白质结合，已获得兔C反应蛋白（CRP）的二维（2D）晶体。通过与脂质的特异性结合和非特异性吸附，获得了两种不同类型的CRP晶体阵列。对经负染的标本进行电子晶体学分析表明，通过特异性结合形成的CRP二维晶体的晶胞参数为a = 81埃，b = 78埃，γ = 118.35度，通过非特异性吸附形成的晶胞参数为a = 74埃，b = 67埃，γ = 95.5度，两者的层群均为p1。分别在26埃和22埃的分辨率下获得了投影图。结果表明，在二维阵列中仅包装有CRP的单体，并且在两种类型的晶体中，脂质单层上单体的取向不同。通过比较这两个投影图，得出了CRP单体的初步形状。已提出了寡聚CRP五聚体结构的模型。
