Chang CH, Yu SD, Chuang TK, Liang CN
Department of Chemical Engineering, National Cheng Kung University, Tainan, 70101, Taiwan, Republic of China
J Colloid Interface Sci. 2000 Jul 15;227(2):461-468. doi: 10.1006/jcis.2000.6887.
This study investigated the roles of gamma-globulin in the dynamic interfacial behavior of dipalmitoyl phosphatidylcholine (DPPC)/gamma-globulin monolayers at air/liquid interfaces at 25 degrees C. The surface tension behavior demonstrated that gamma-globulin had a large adsorption time scale. Moreover, the surface pressure-area hysteresis behavior of adsorbed gamma-globulin monolayers suggested that no significant desorption occurred during the compression stage, and the respreading of gamma-globulin molecules at the interface during the expansion stage was slow. From the hysteresis behavior of adsorbed gamma-globulin monolayers with spread DPPC molecules, it was found that gamma-globulin molecules were expelled from the interface as DPPC molecules were in a condensed state. The squeeze-out of gamma-globulin molecules seemed to induce the loss of DPPC molecules at the interface with the extent depending on the initial gamma-globulin surface concentration. Furthermore, the expelled gamma-globulin molecules re-entered the monolayer and participated in the surface pressure increase during the following expansion stage. The exclusion of gamma-globulin associated with the removal of DPPC during monolayer compression and the re-entry of gamma-globulin during subsequent monolayer expansion represented a mechanism for DPPC depletion and gamma-globulin enrichment at the interface, which may explain the inhibitory effect of certain proteins on the surface activity of DPPC. Copyright 2000 Academic Press.
本研究调查了γ-球蛋白在25℃下空气/液体界面处二棕榈酰磷脂酰胆碱（DPPC）/γ-球蛋白单分子层动态界面行为中的作用。表面张力行为表明γ-球蛋白具有较长的吸附时间尺度。此外，吸附的γ-球蛋白单分子层的表面压力-面积滞后行为表明，在压缩阶段没有明显的解吸发生，并且在膨胀阶段γ-球蛋白分子在界面处的再铺展缓慢。从吸附的γ-球蛋白单分子层与铺展的DPPC分子的滞后行为发现，当DPPC分子处于凝聚态时，γ-球蛋白分子从界面被排出。γ-球蛋白分子的挤出似乎导致界面处DPPC分子的损失，其程度取决于初始γ-球蛋白表面浓度。此外，被排出的γ-球蛋白分子在随后的膨胀阶段重新进入单分子层并参与表面压力的增加。在单分子层压缩过程中与DPPC去除相关的γ-球蛋白的排出以及在随后的单分子层膨胀过程中γ-球蛋白的重新进入代表了一种在界面处DPPC消耗和γ-球蛋白富集的机制，这可能解释了某些蛋白质对DPPC表面活性的抑制作用。版权所有2000年学术出版社。
