Keller F, Hanke W, Trissl D, Bakker-Grunwald T
Universität Osnabrück, Department of Microbiology, F.R.G.
Biochim Biophys Acta. 1989 Jun 26;982(1):89-93. doi: 10.1016/0005-2736(89)90178-8.
Pore-forming protein from Entamoeba histolytica forms cation-selective channels in planar bilayers. With increasing potentials, the open-state probability of these channels decreases, and channel aggregates collapse (Young, J.D.-E. and Cohn, Z.A. (1985) J. Cell. Biochem. 29, 299-308). In this communication we report the following observations: (i) incorporation of the pore in black-lipid membranes was stimulated by membrane potential, (ii) pores were rectifying, (iii) breakdown of pores resulted in a continuous spectrum of subconductance states, (iv) the open-state probability increased strongly with pH. This pattern of behaviour is similar to that of the barrel-stave aggregates (alamethicin and related toxins). We therefore conclude that the amebal pores, like those of the barrel-stave class, may consist of complexes involving variable numbers of membrane-spanning subunits.
溶组织内阿米巴的成孔蛋白在平面双层膜中形成阳离子选择性通道。随着电位增加，这些通道的开放状态概率降低，且通道聚集体瓦解（扬，J.D.-E.和科恩，Z.A.（1985年）《细胞生物化学杂志》29卷，299 - 308页）。在本通讯中，我们报告以下观察结果：（i）膜电位刺激孔在黑脂质膜中的掺入，（ii）孔具有整流性，（iii）孔的破裂导致亚电导状态的连续谱，（iv）开放状态概率随pH值强烈增加。这种行为模式类似于桶板聚集体（短杆菌肽A及相关毒素）。因此我们得出结论，阿米巴孔与桶板类孔一样，可能由涉及可变数量跨膜亚基的复合物组成。
