Immunoglobulin domain

Immunoglobulin Domain

Structure of an immunoglobulin domain.

The immunoglobulin domain is a type of protein domain that is found in a wide variety of proteins, including antibodies, cell surface receptors, and cell adhesion molecules. These domains are characterized by a specific folding pattern known as the immunoglobulin fold, which consists of a two-layer sandwich of beta sheets.

Structure

The immunoglobulin domain typically consists of about 70 to 110 amino acids arranged in a beta-sandwich structure. This structure is composed of two beta sheets that are held together by hydrophobic interactions. The beta sheets are usually composed of seven to nine beta strands.

The immunoglobulin fold is highly stable and can be found in a wide variety of proteins, not just those involved in the immune system. This stability is due to the extensive hydrogen bonding and hydrophobic interactions between the beta strands.

Function

Immunoglobulin domains are involved in a variety of functions, depending on the protein in which they are found. In antibodies, they are responsible for antigen binding and recognition. In cell adhesion molecules, they mediate cell-cell interactions. In receptors, they are involved in signal transduction.

The versatility of the immunoglobulin domain is due to its ability to form stable structures that can be easily modified to bind different ligands or interact with other proteins.

Types of Immunoglobulin Domains

There are several types of immunoglobulin domains, including:

• Variable (V) domains: Found in antibodies and T-cell receptors, these domains are responsible for antigen recognition and binding.
• Constant (C) domains: Found in antibodies, these domains provide structural support and mediate effector functions.
• Joining (J) domains: Involved in the recombination of antibody genes.

Applications

Immunoglobulin domains are used in a variety of biotechnological and therapeutic applications. They are used in the design of monoclonal antibodies for the treatment of diseases such as cancer and autoimmune disorders. They are also used in the development of biosensors and diagnostic assays.

Related Pages

• Antibody
• Cell adhesion molecule
• Receptor (biochemistry)
• Monoclonal antibody