INTERACTION OF SPIKE PROTEIN RECEPTOR AND HEPARIN IN VIRAL ENVELOPE MODELS

Since the World Health Organization (WHO) declared a global pandemic due to the new coronavirus SARS-CoV-2, which causes COVID-19, it has been growing the importance of developing long-term research aimed at the development of antiviral drugs, as well as robust and rapid vaccines and also sensors to detect viral infection. An important point for this is the knowledge of the chemical and morphological composition of viruses, as well as the biological process associated with their infection, replication, and interaction with the host cell. The following work aimed to study the interaction of the Spike protein receptor (RBD) of Sars-Cov2 with heparins with Langmuir films of phospholipids, which serve as cell membrane models. The phospholipid t used was dipalmitodylphosphatidylserine (DPPS), miming the viral envelope. The interaction of the compounds with the lipid monolayers was evaluated through measurements of surface potential and surface pressure-area isotherms, compression-decompression cycles, surface pressure-time stability, and surface rheology using oscillating barriers and Brewster Angle Microscopy (BAM). Incorporating RBD and heparin into the DPPS monolayers changed the thermodynamic parameters shifting the isotherms. Rheological measurements showed that the biomolecules decreased the monolayer viscoelasticity modulus, making the film more fluid, and BAM indicated the morphological pattern for each monolayer. The results were evaluated from the perspective of possible biological implications, inferred from the effects caused by the bioactive on the artificial membranes so that from the results obtained through the experimental analyses, it was possible to determine how the interaction between the compounds with the phospholipid.This work was supported by FAPESP (2022/03736-7) and CNPq