LRP-1 Binds Fibrinogen in a Sialylation-Dependent Manner: A Quartz Crystal Microbalance Study

Area of Science:

• Cardiovascular biology
• Molecular mechanisms of atherosclerosis
• Receptor-ligand interactions

Background:

• Cardiovascular disease (CVD) is a leading cause of death, primarily driven by atherosclerosis.
• Atherosclerosis involves fibrofatty plaque formation, influenced by clotting factor fibrinogen.
• Impaired efferocytosis, a cellular clearance process, contributes to atherosclerosis progression.

Purpose of the Study:

• To investigate the interaction between fibrinogen and the LRP-1 receptor.
• To determine the role of LRP-1 in atherosclerosis and efferocytosis.
• To explore how sialylation affects LRP-1's binding efficacy to fibrinogen.

Main Methods:

• Utilized quartz crystal microbalance with dissipation monitoring (QCM-D) for receptor-ligand interaction analysis.
• Employed protein docking simulations to identify binding sites.
• Investigated the impact of sialidase on LRP-1 efficacy.

Main Results:

• Identified fibrinogen as a ligand for LRP-1, characterizing their binding.
• Demonstrated that desialylation of LRP-1 significantly reduces its binding affinity for fibrinogen.
• Protein docking revealed the N-terminus of fibrinogen's α domain as the LRP-1 binding site.
• Sialylated glycans at T894 and T935 on LRP-1 may mediate binding and stabilize its structure.

Conclusions:

• Impaired LRP-1-fibrinogen binding due to LRP-1 desialylation is a potential cause of defective efferocytosis in atherosclerosis.
• This mechanism offers insight into the progression of atherosclerotic plaques.
• Understanding this interaction could inform future therapeutic strategies for CVD.