Luchian Tudor
Faculty of Physics, Department of Biophysics and Medical Physics, 'Alexandru I. Cuza' University, Blvd. Carol I no 11, Iasi, RO-6600 Romania.
J Biol Phys. 2005 Jan;31(1):23-33. doi: 10.1007/s10867-005-3303-9.
In this paper, we examined the influence exerted by calcium ions upon physical properties of lipids constituting an artificial membrane. Our strategy was to study changes on alamethicin oligomer kinetic features embedded into such an artificial membrane. At neutral pH and in the presence of calcium ions, we observed an increase in the number of alamethicin monomers that oligomerize within the membrane, forming a multi-substate nanopore. We make the argument that calcium ions binding within the interface between the hydrophobic and the hydrophilic regions of the biomembrane causes a sizeable alteration of the physical properties of neutral lipid membranes. This in turn is seen to influence the translocation rates of alamethicin monomers from the solution adjacent to the biomembrane and leads to an augmentation in the subunit composition of the alamethicin oligomers, leaving the electrical conductance of the substates and their kinetics mainly unchanged.
在本文中，我们研究了钙离子对构成人工膜的脂质物理性质的影响。我们的策略是研究嵌入这种人工膜中的短杆菌肽寡聚物动力学特征的变化。在中性pH值和钙离子存在的情况下，我们观察到膜内寡聚化的短杆菌肽单体数量增加，形成了多亚态纳米孔。我们认为，钙离子结合在生物膜疏水和亲水区域之间的界面内，会导致中性脂质膜的物理性质发生相当大的改变。这反过来又会影响短杆菌肽单体从生物膜相邻溶液中的转运速率，并导致短杆菌肽寡聚物的亚基组成增加，而亚态的电导及其动力学基本保持不变。
