Dimitrova Mariana N., Tsekov Roumen, Matsumura Hideo, Furusawa Kunio
Membrane Fusion Lab, Electrotechnical Laboratory, AIST, MITI, Tsukuba, 305 8568, Japan
J Colloid Interface Sci. 2000 Jun 1;226(1):44-50. doi: 10.1006/jcis.2000.6772.
The adsorption of lysozyme and cytochrome C on phosphatidylcholine liposomes essentially changes the physical properties of the phospholipid membranes and under certain circumstances greatly affects the stability of the colloid dispersion by inducing bridging liposome flocculation. This study was designed to examine experimentally the influence of liposome size on two kinetic parameters of the flocculation, its rate constant and activation energy. As the liposome radius increased in the range 50-500 nm, the activation energy tended to decrease, resulting in an increased flocculation rate, except for the flocculation of 400-nm liposomes, which was greatly impeded. The pronounced influence of the liposome size on the flocculation rate constant was evident, since a well-defined minimum in the kinetic rate of flocculation of 400-nm liposomes was detected experimentally. The obtained nonlinear radius dependencies of the flocculation rates and activation energies are interpreted in terms of the bridging mechanism of the protein-induced liposome flocculation and the supplementary concept of the stability of thin liquid films formed between approaching protein-adsorbed liposomes. Copyright 2000 Academic Press.
溶菌酶和细胞色素C在磷脂酰胆碱脂质体上的吸附本质上改变了磷脂膜的物理性质，在某些情况下，通过诱导桥连脂质体絮凝极大地影响了胶体分散体的稳定性。本研究旨在通过实验研究脂质体大小对絮凝的两个动力学参数，即其速率常数和活化能的影响。当脂质体半径在50 - 500 nm范围内增加时，活化能趋于降低，导致絮凝速率增加，但400 nm脂质体的絮凝受到极大阻碍。脂质体大小对絮凝速率常数有显著影响，因为通过实验检测到400 nm脂质体的絮凝动力学速率存在明确的最小值。根据蛋白质诱导脂质体絮凝的桥连机制以及接近蛋白质吸附脂质体之间形成的薄液膜稳定性的补充概念，对所获得的絮凝速率和活化能的非线性半径依赖性进行了解释。版权所有2000年学术出版社。
