Mechanistic Investigation of Interactions between Steroidal Saponin Digitonin and Cell Membrane Models

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• 作者：Nataliya Frenkel ; Ali Makky ; Ikhwan Resmala Sudji ; Michael Wink ; Motomu Tanaka
• 刊名：Journal of Physical Chemistry B
• 出版年：2014
• 出版时间：December 18, 2014
• 年：2014
• 卷：118
• 期：50
• 页码：14632-14639
• 全文大小：396K
• ISSN：1520-5207

文摘

Digitonin is an amphiphilic steroidal saponin, a class of natural products that can bind to cholesterol and lyse cells. Despite the known cell membrane lysis activity, it remains unclear how it interacts with cell membranes. In the present work, the interaction mechanism between digitonin and cell membrane models has quantitatively been investigated using a combination of physical techniques. It has been demonstrated that digitonin molecules bind specifically to cholesterol in the membrane, resulting in the formation of cholesterol鈥揹igitonin complexes on the membrane surface by removing cholesterol from the membrane core. Changes in the mass density and the film mechanics caused by the digitonin were determined by using quartz crystal microbalance with dissipation (QCM-D), and the combination of X-ray reflectivity (XRR) and dual polarization interferometry (DPI) yielded the hydration level of the cholesterol鈥揹igitonin complexes. From differential scanning calorimetry (DSC) analysis, supporting evidence was obtained that cholesterol was removed from the membrane core.