X-RAY-DIFFRACTION ANALYSIS OF MATRIX PORIN, AN INTEGRAL MEMBRANE-PROTEIN FROM ESCHERICHIA-COLI OUTER MEMBRANES
X-RAY-DIFFRACTION ANALYSIS OF MATRIX PORIN, AN INTEGRAL MEMBRANE-PROTEIN FROM ESCHERICHIA-COLI OUTER MEMBRANES
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DOI：
10.1016/0022-2836(83)90079-7
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发表时间：
1983-01-01
影响因子：
5.6
通讯作者：
ROSENBUSCH, JP
中科院分区：
文献类型：
--
作者：
GARAVITO, RM;JENKINS, J;ROSENBUSCH, JP
使用聚乙二醇或盐生成的两相体系结晶形成穿过大肠杆菌外膜的通道的完整膜蛋白Porin。蛋白质-洗涤剂复合体的单分散性和均一性是可重复形成符合X射线结构分析的晶体的先决条件。通过改变pH值、洗涤剂和缓冲液类型，可以得到3种不同习性的大晶体，并对其中2种习性进行了讨论。四方晶型(空间群P42，晶胞尺寸a=b=155，c=172。)适用于X射线分析。低温导致空间群改变为P4222，在不对称单元中只有一个三聚体。这种晶型的衍射率超过2.9。六方晶型(空间群P6322，晶胞尺寸a=b=93，c=220)的分辨率限制为4.5，但揭示了一种与二维膜状晶体阵列非常相似的堆积排列。
An integral membrane protein forming channels across E. coli outer membranes, porin, was crystallized using a polyethylene glycol or salt-generated 2-phase system. Monodispersity and homogeneity of protein-detergent complexes are prerequisites for reproducible formation of crystals amenable to X-ray structural analysis. By varying pH, detergent and buffer type, large crystals of 3 different habits can be obtained, 2 of which are discussed. The tetragonal form (space group P42; unit cell dimensions, a = b = 155 .ANG., c = 172 .ANG.) is suitable for X-ray analysis. Low temperature induces a change of the space group to P4222, with a single trimer in the asymmetric unit. This crystal form diffracts to a resolution beyond 2.9 .ANG.. The hexagonal crystal form (space group P6322, unit cell dimensions, a = b = 93 .ANG., c= 220 .ANG.) is limited in resolution to 4.5 .ANG. but reveals a packing arrangement very similar to that in 2-dimensional membrane-like crystalline arrays.