The ₉₅RGD₉₇ sequence on the Aα chain of fibrinogen is essential for binding to its erythrocyte receptor

Abstract

BackgroundErythrocyte aggregation, a cardiovascular risk factor, is increased by high plasma fibrinogen levels. Here, the effect of different fibrinogen mutations on binding to its human erythrocyte receptor was assessed in order to identify the interaction sites.MethodsThree fibrinogen variants were tested, specifically mutated in their putative integrin recognition sites on the Aα chain (mutants D97E, D574E and D97E/D574E) and compared with wild-type fibrinogen.ResultsAtomic force microscopy-based force spectroscopy measurements showed a significant decrease both on the fibrinogen–erythrocyte binding force and on its frequency for fibrinogen with the D97E mutation, indicating that the corresponding arginine–glycine–aspartate sequence (residues 95–97) is involved in this interaction, and supporting that the fibrinogen receptor on erythrocytes has a β3 subunit. Changes in the fibrin clot network structure obtained with the D97E mutant were observed by scanning electron microscopy.ConclusionThese findings may lead to innovative perspectives on the development of new therapeutic approaches to overcome the risks of fibrinogen-driven erythrocyte hyperaggregation.

Sialic acids rather than glycosaminoglycans affect normal and sickle red blood cell rheology by binding to four major sites on fibrinogen

“…T ), T = 310 K). The second site encompasses the RGD tripeptide (95‐97) involved in the binding of fibrinogen to RBCs, supporting the involvement of the sialylated RGD‐dependent αvβ3 integrin in fibrinogen binding to RBCs . The third and fourth binding sites, with binding energies of −7.2 and − 7.5 kcal/mol, respectively, were located on β (mainly) and γ‐globular heads of fibrinogen.…”

A mathematical model of fibrinogen-mediated erythrocyte–erythrocyte adhesion

“…Fibrinogen is involved in the coagulation cascade, it has a crucial role in blood clotting and has been identified as a major independent risk factor for cardiovascular diseases 11 – 20 . An increase in fibrinogen plasma concentration promotes erythrocyte aggregation 21 . Using atomic force microscopy (AFM)-based force spectroscopy, we previously identified the specific receptor for fibrinogen on the erythrocyte membrane 12 , 17 , 22 .…”