Monitoring of cytochrome c adsorption at supported lipid membranes using multiharmonic QCM method

Cell apoptosis causes release of cytochrome c (cyt c) in programmed cell death. It can be used as biomarker to evaluate chemotherapy efficacy. However, detection and study of cyt c interaction with lipid membranes proves to be a challenging task. Recent studies suggest innovative development in cyt c detection by binding it to specific DNA aptamers. To achieve this goal, it is necessary to provide surface with bound cyt c. Our research was focused on preparation of supported lipid membranes on the gold surface of the quartz crystal. Lipid membranes were prepared by liposome fusion at the surface of 1-dodecanethiol chemisorbed at gold surface of the crystal. The liposomes were composed of a mixture of L-α-Phosphatidylcholine (lecithin) and Dimyristoyl phosphatidylglycerol (DMPG), which were used in different ratios. Subsequent formation of the lipid membrane was monitored by multiharmonic quartz crystal microbalance (QCM). Cyt c was applied on lipid layer and we observed changes in fundamental and several higher harmonic frequencies. Energy dissipation changes were recorded as well. The data on frequency and dissipation changes were used for the analysis of the viscoelastic properties of adsorbed layers.

This work has been supported by Science Grant Agency VEGA (project No. 1/0419/20).