It is known that lipids of different compositions play a fundamental role in the organization of cell membranes. Membranes consist of highly mobile individual molecules (mainly lipids and proteins) in dynamic equilibrium undergoing transient interactions organized into a three-dimensional supramolecular structure. The lipid and protein components of the membrane are not held together by covalent interactions. Recent studies showed that a lipid membrane has specific domains containing sphingolipids (SM) and cholesterol (Ch) known as lipid rafts. The latter have a liquid ordering phase (dense phase) organized in the environment of liquid-crystalline or fluidic liquid disordering phase. Changes in lipid composition caused by the nonspecific influence of various amphiphilic and hydrophobic drugs, viruses, etc., are supposed to modify the plasma membrane, which in turn affects the membrane receptors.

Here, we investigated a model of lipid raft formation and the influence on its lipid compositions of the antiviral drug remdesivir which is used for the treatment of severe cases of COVID-19 disease. FTIR molecular bands were chosen as spectral markers. With FTIR spectroscopy, the marker spectral regions for the lipid rafts were 1) the region of C=O vibrations of 1670-1640 cm^-1, 2)1570-1520 cm^-1 corresponding to C=C vibrations, and 3) the region of 1400-1364 cm^-1 assigned to C -H bending vibrations. In the case of the liquid-ordered phase, the IR absorption bands centered at 1644 cm^-1 and 1548 cm^-1 shift towards the high frequency, and the band at 1400 cm^-1 towards the low frequency, which indicates a decrease in the raft domain integrity in the membrane.

In addition to DOPC, changes in the ratio of lipids (SM and Ch) and remdesivir are able to disrupt the structure of the lipid rafts. Following the changes in the structure of the lipid rafts, we could clear up the mechanism of the influence of environmental factors including drugs and propose an additional test.