What is a hinge region of a protein?

Hinge regions are stretches of a protein that can be involved in the propagation of conformational changes e.g. from the active site to the rest of the protein structure, including other subunits. They could be small loops in between secondary structures. What is the function of the hinge region in an antibody?
The hinge region is a stretch of heavy chains between the Fab and Fc portions. Its unique structure and position provide segmental flexibility, which is essential for normal functioning of antibodies (e.g., for crosslinking two antigens or binding two antigenic determinants on the same antigen molecule).

Does IgG have hinge region?

Both IgM and IgE lack a hinge region but each contains an extra heavy-chain domain. Which of the following amino acid found in the hinge region?
Which of the following amino acid is found in the hinge region? Explanation: Hinge region is found in IgG, IgA, and IgD to provide flexibility in its structure. These regions are rich in proline and cysteine and basically found between two Fab arms of the Y-shaped antibody.

What is the constant region?

Medical Definition of constant region : the part of the polypeptide chain of a light or heavy chain of an antibody that ends in a free carboxyl group −COOH and that is relatively constant in its sequence of amino acid residues from one antibody to another. What is hinge region in immunology?

The hinge region is a flexible amino acid stretch in the central part of the heavy chains of the IgG and IgA immunoglobulin classes, which links these 2 chains by disulfide bonds.

Frequently Asked Questions(FAQ)

What is the Fab region in antibody?

The fragment antigen-binding (Fab fragment) is a region on an antibody that binds to antigens. It is composed of one constant and one variable domain of each of the heavy and the light chain. These domains shape the paratope — the antigen-binding site — at the amino terminal end of the monomer.

Where do antibodies bind?

Peptides binding to antibodies usually bind in the cleft between the V regions of the heavy and light chains, where they make specific contact with some, but not necessarily all, of the hypervariable loops. This is also the usual mode of binding for carbohydrate antigens and small molecules such as haptens.

What is nuclear signaling?

Nuclear signaling events typically result in the generation of a huge and relatively stable complex composed of a functional transcriptional activator protein, additional proteins that bind to the activator protein, and the RNA polymerase and associated proteins bound at the start site of transcription.

What is nuclear receptor signaling?

Abstract. Nuclear receptors are activated by lipid-soluble signals (e.g., steroid hormones) that cross the plasma membrane. Once activated, most function as transcription factors to control gene expression for numerous biological processes.

What are types of receptors?

Which is known as Millionaire molecule?

High Molecular Weight: Because of its high molecular weight (900,000- 1000,000), it is often called macroglobulin and the ‘millionaire molecule’. Presence of J chains.

What is meant by immunoglobulin?

Immunoglobulin: A protein produced by plasma cells and lymphocytes and characteristic of these types of cells. Immunoglobulins play an essential role in the body’s immune system. They attach to foreign substances, such as bacteria, and assist in destroying them. Immunoglobulin is abbreviated Ig.

Which immunoglobulin has AJ chain?

IgM A J chain is a protein component of the antibodies IgM and IgA. It is a 137 residue polypeptide, encoded by the IGJ gene.

Which IG can cross the placenta?

IgG is the only antibody class that significantly crosses the human placenta. This crossing is mediated by FcRn expressed on syncytiotrophoblast cells.

Where is IgG?

IgG. IgG antibodies are found in all body fluids. They are the smallest but most common antibody (75% to 80%) of all the antibodies in the body. IgG antibodies are very important in fighting bacterial and viral infections.

What is heavy and light chain?

IgG antibodies are large molecules, having a molecular weight of approximately 150 kDa, composed of two different kinds of polypeptide chain. One, of approximately 50 kDa, is termed the heavy or H chain, and the other, of 25 kDa, is termed the light or L chain (Fig. 3.2).

What is the variable vs constant region?

The constant region determines the mechanism used to destroy antigen. Antibodies are divided into five major classes, IgM, IgG, Iga, IgD, and IgE, based on their constant region structure and immune function. The variable region is further subdivided into hypervariable (HV) and framework (FR) regions.

What is the variable region?

variable region –> V region. (Science: molecular biology) Those regions in the amino acid sequence of both the heavy and the light chains of immunoglobulins where there is considerable sequence variability from one immunoglobulin to other of the same class, in contrast to constant sequence (C) regions.

What is the function of C region of IgG?

Since the mid-twentieth century, the Ig molecule has been considered a bifunctional molecule consisting of two largely independent regions, a V region responsible for specificity and affinity, and a C region responsible for effector functions such as complement activation and interaction with FcRs.

What is the name of the hypervariable region of immunoglobulin?

Three areas in the V region of light and heavy chains are highly variable and form distinct loops in the immunoglobulin protein structure. They are termed CDR1, CDR2, and CDR3. The other areas of the V region are more consistent in amino acid sequence and they are referred to as the framework regions (see Figure).

What causes class switching?

Class switching occurs after activation of a mature B cell via its membrane-bound antibody molecule (or B cell receptor) to generate the different classes of antibody, all with the same variable domains as the original antibody generated in the immature B cell during the process of V(D)J recombination, but possessing …

Where are hypervariable regions located on an antibody?

Antibodies. In antibodies, hypervariable regions form the antigen-binding site and are found on both light and heavy chains. They also contribute to the specificity of each antibody. In a variable domain, the 3 H_V segments of each heavy or light chain fold together at the N-terminus to form an antigen binding pocket.

What is the difference between Fab and Fc?

The fragment crystallizable (Fc) region contains only constant regions from the heavy chains (C_H), but the fragment antigen-binding region (Fab) includes both a constant domain and the variable domains of both the heavy and light chains (VH and C_L).

What determines complementarity region?

Complementarity-determining regions (CDRs) are part of the variable chains in immunoglobulins (antibodies) and T cell receptors, generated by B-cells and T-cells respectively, where these molecules bind to their specific antigen. A set of CDRs constitutes a paratope.

What is the function of Fab?

Fabs are a common form-factor for monoclonal antibodies designated for therapeutic use. The Fab abciximab, which inhibits blood clotting, works by disabling glycoprotein IIb/IIIa found on platelets.