Mikes V, Milat M L, Pugin A, Blein J P
Unité Associée Phytopharmacie Phytobiologie Cellulaire, INRA-Université de Bourgogne, Dijon, France.
Biochim Biophys Acta. 1994 Oct 12;1195(1):124-30. doi: 10.1016/0005-2736(94)90018-3.
The interactions of two beticolins, Cercospora beticola toxins, and of their magnesium complexes with liposomes or plasma membrane were studied. The fluorometric pH titration curves of beticolins in liposomes and in plasma membranes reveal the presence of the dissociated form of beticolins. The concentration of the magnesium complex in these membranes increases at high pH. The partition coefficient of beticolin-1 on liposomes is 3-fold higher than that of beticolin-2 and the fluorescence of both compounds on liposomes is similar. The addition of magnesium to liposomes causes a 40-fold and 20-fold increase in the partition coefficient of beticolin-1 and -2, respectively, as a result of the interactions between membrane, magnesium and beticolins. Beticolins react to a delta pH across the liposome membrane but the formation of the magnesium complex completely abolishes this effect.
研究了两种甜菜素、甜菜尾孢菌毒素及其镁配合物与脂质体或质膜的相互作用。甜菜素在脂质体和质膜中的荧光pH滴定曲线表明存在甜菜素的解离形式。在高pH值下，这些膜中镁配合物的浓度会增加。甜菜素-1在脂质体上的分配系数比甜菜素-2高3倍，且两种化合物在脂质体上的荧光相似。由于膜、镁和甜菜素之间的相互作用，向脂质体中添加镁会使甜菜素-1和-2的分配系数分别增加40倍和20倍。甜菜素会对脂质体膜两侧的pH差值产生反应，但镁配合物的形成会完全消除这种效应。
