PROBING FIBRINOGEN STRUCTURE: INSIGHTS FROM LIMITED PROTEOLYSIS, PEPTIDES, AND MONOCLONAL ANTIBODIES

Aim. The aim of this study was to analyze the prospects of using antibodyes, peptides and proteases in investigating fibrinogen structure and function. Methods. Polyacrylamide gel electrophoresis, western blotting, turbidimetry, electron microscopy. Results. Since antibodies are specific to a small sequence of amino acid residues, monoclonal antibodies can be used to investigate the importance of a specific site on fibrinogen. For example, using the 1-5A antibodies, which are specific to the C-terminal region of the Aα-chain of fibrinogen, the importance of these regions in the lateral association of protofibrils was established. The study indicates that the presence of various antibodies, each specific to a relatively small region of the fibrinogen molecule, can cause different effects on the functioning of the molecule. It has been demonstrated that synthetic peptide Аα195-205 inhibits the stage of fibrin protofibril formation, while peptide γ69-77 inhibits the lateral association of protofibrils. Another approach in the study of proteins is limited proteolysis. For example, using proteases from the culture medium of B. thuringiensis and the venom of G. halys we separated the functional role of different parts of fibrin(ogen) αС-region in its functioning. Conclusions. Thus, it is important to acknowledge that the described approaches in protein research each have their own advantages and disadvantages, and scientists may choose them based on specific research objectives. Funding. The work was carried out within the framework of scientific research works projects of young scientists of the National Academy of Sciences of Ukraine: «The influence of agonists and antagonists of integrin receptors on the functional effects of platelets» (2023–2024, State registration number 0123U103023).