Benz R, Janko K, Läuger P
Biochim Biophys Acta. 1979 Mar 8;551(2):238-47. doi: 10.1016/0005-2736(89)90002-3.
Incorporation of the matrix protein (porin) from the outer membrane of Escherichia coli into black lipid films results in the formation of ion-permeable pores with a single-pore conductance of the order of 2 nS (in 1 M KCl). Information on the structure of this pore has been obtained by determining the selectivity for various species differing in charge and size. From the permeability of the pore for large organic ions (Tris+, glucosamine+, Hepes-) a minimum pore diameter of 0.8 nm is estimated. At neutral pH the pore is two to four times more permeable for alkali ions than for chloride. On the basis of the observed pH dependence of permeability, this cationic selectivity is explained by the assumption that the pore contains fixed negative charges.
将来自大肠杆菌外膜的基质蛋白（孔蛋白）掺入黑色脂质膜中会导致形成离子可渗透的孔，其单孔电导约为2 nS（在1 M KCl中）。通过确定对电荷和大小不同的各种离子的选择性，已获得有关该孔结构的信息。根据该孔对大有机离子（Tris +、葡糖胺 +、Hepes -）的渗透性，估计最小孔径为0.8 nm。在中性pH下，该孔对碱金属离子的渗透性比对氯离子高两到四倍。基于观察到的渗透性对pH的依赖性，这种阳离子选择性是通过假设孔中含有固定负电荷来解释的。
