Nanoscale physics

The influence of SARS-CoV-2 receptor binding domain on the model lipid membrane structure: a SANS study 
Soloviov D.V.1,2, Doroshenko I.Yu.2, Nikolaienko T.Yu.2, Ivankov O.I.1,2, Bulavin L.A.2
1 Institute for Safety Problems of Nuclear Power Plants of the NAS of Ukraine, Lysogirska Street, 12, Kyiv-03028, Ukraine.
E-mail: dimkaupml@gmail.com
2 Faculty of Physics, Taras Shevchenko National University of Kyiv. Volodymyrska Street, 64/13, Kyiv-01601, Ukraine. 

Detailed information about the structure and properties of lipid membranes is essential for building reliable models describing response of living cell to different environmental perturbations, of both physical and chemical origin [1]. Importance of such kind of data is inherently related to strong mutual influences of the components of living systems. This influence makes it impossible to reduce the dynamics of interaction of living cell with a viral agent (with SARS-CoV-2 being one of the latest well-known examples) to only considering the binding receptors dynamics, because the structure and properties of the membrane itself, if influenced by the viral agent, can modulate a number of biophysical processes and therefore affect the penetration of the agent. 
In this contribution we present our recent results obtained by small-angle neutron scattering in multi-component liquid systems, containing both model membranes (DMPC lipid vesicles), cholesterol and melatonin adducts in various concentrations and SARS-CoV-2 receptor binding domain (RBD) - a part of the viral spike, which is responsible for its biding with cells receptors. Obtained data uncovers geometrical properties of the vesicles (like vesicle diameter and bilayer thickness) and provides a way to test the existence of direct interactions between RBD and membrane, as opposed to the interaction by virtue of membrane receptor.
 
The work has been supported by the National Research Foundation of Ukraine (project No. 2020.01/0103).

1.	Bulavin L.A., Mikhailov A.E., Kuzmichev P.K., Chupin V.V., Borshchevskiy V.I., Chizhov I.V., D.V. Soloviov, Influence of Cholesterol Concentration on Bacteriorhodopsin Photocycle // Ukr. J. Phys.- 2020.-65(9).-P. 778-778.