Related Experiment Video
Updated: Apr 27, 2026
Characterization of Glycoproteins with the Immunoglobulin Fold by X-Ray Crystallography and Biophysical Techniques
Published on: July 5, 2018
Molecular recognition of Fc-specific ligands binding onto the consensus binding site of IgG: insights from molecular
Hong-Fei Tong1, Dong-Qiang Lin, Qi-Lei Zhang
1State Key Laboratory of Chemical Engineering, Department of Chemical and Biological Engineering, Zhejiang University, Hangzhou, 310027, China.
Insights
Hydrophobic interactions drive binding between Immunoglobulin G (IgG) Fc domain and its ligands. Key amino acids like tryptophan and tyrosine on ligands, and specific Fc residues, are crucial for this interaction.
Area of Science:
- Biochemistry
- Molecular Biology
- Immunology
Background:
- Immunoglobulin G (IgG) is vital in clinical applications.
- The consensus binding site (CBS) on the IgG Fc domain mediates ligand interactions.
Purpose of the Study:
- To investigate molecular interactions between the IgG Fc domain's CBS and natural Fc-specific ligands.
- To identify key residues and binding forces driving Fc-ligand complex formation.
Main Methods:
- Molecular simulation techniques were employed.
- Computational alanine scanning was used to identify hot spots.
Main Results:
- Hydrophobic interactions are the primary driving force for Fc-ligand binding.
- Tryptophan and tyrosine residues on ligands, and Fc residues Met252, Ile253, Asn434, His435, and Tyr436, are critical.
- Two distinct binding modes, tryptophan- and tyrosine-based, were identified.
Conclusions:
- Understanding these interactions facilitates rational design of high-affinity, specific Fc-ligand binders.
- The study provides guidelines for developing targeted therapeutics and diagnostic tools.
Abstract:
Immunoglobulin G (IgG) plays an important role in clinical diagnosis and therapeutics. Meanwhile, the consensus binding site (CBS) on the Fc domain of IgG is responsible for ligand recognition, especially for Fc-specific ligands. In this study, molecular simulation methods were used to investigate molecular interactions between the CBS of the Fc domain and seven natural Fc-specific ligands. The analysis on the binding energy of the Fc-ligand complex indicated that hydrophobic interactions provide the main driving force for the Fc-ligand binding processes. The hot spots on the ligands and Fc were identified with the computational alanine scanning approach. It was found that the residues of tryptophan and tyrosine on the ligands have significant contributions for the Fc-ligand binding, while Met252, Ile253, Asn434, His435, and Tyr436 are the key residues of Fc. Moreover, two binding modes based on tryptophan or tyrosine were summarized and constructed according to the pairwise interaction analysis. Guidelines for the rational design of CBS-specific ligands with high affinity and specificity were proposed.
Related Concept Videos
01:10Antibody Structure
01:10Antibody Structure
Antibodies, also known as immunoglobulins (Ig), are essential players of the adaptive immune system. These antigen-binding proteins are produced by B cells and make up 20 percent of the total blood plasma by weight. In mammals, antibodies fall into five different classes, which each elicits a different biological response upon antigen binding.
The Y-Shaped Structure of Antibodies Consists of Four Polypeptide Chains
Antibodies consist of four polypeptide chains: two identical heavy...
01:31Immunoglobulin-like Cell Adhesion Molecules
Ig-CAMs exhibit either homophilic binding (to other Ig-CAMs) or heterophilic binding (to other ligands such as integrins). While most Ig-CAMs...
02:40Ligand Binding Sites
Protein-ligand interactions are quite specific; even though numerous potential ligands surround a cellular protein at any given time, only a particular ligand can bind to that protein. Moreover, a ligand binds only to a dedicated area on the surface of the protein, known as the...
02:40Ligand Binding Sites
01:49Conserved Binding Sites
Binding sites are often located in large pockets, and if their location on a protein’s surface is unknown, it can be predicted using various approaches. The energetic method computationally...