Table of Contents
How does an antigen bind with a specific antibody?
The antibody recognizes a unique part of the foreign target, called an antigen. Each tip of the “Y” of an antibody contains a paratope that is specific for one particular epitope (analogous to a lock and key) on an antigen, allowing these two structures to bind together with precision.
What part of the antibody binds to the antigen?
paratope
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.
What is the bond between antibody and antigen?
Antibodies bind antigens through weak chemical interactions, and bonding is essentially non-covalent. Electrostatic interactions, hydrogen bonds, van der Waals forces, and hydrophobic interactions are all known to be involved depending on the interaction sites.
What is it called when antigens bind?
Therefore, most antigens have the potential to be bound by several distinct antibodies, each of which is specific to a particular epitope. The antigen binding receptor on an antibody is called a paratope, and is specific to the epitope of the antigen.
What happens when antibody binds antigen?
Antibodies are produced by specialized white blood cells called B lymphocytes (or B cells). When an antigen binds to the B-cell surface, it stimulates the B cell to divide and mature into a group of identical cells called a clone.
How do antigens bind?
With protein antigens, the antibody molecule contacts the antigen over a broad area of its surface that is complementary to the surface recognized on the antigen. Electrostatic interactions, hydrogen bonds, van der Waals forces, and hydrophobic interactions can all contribute to binding.
How many antigens can an antibody bind to?
Since an antibody has at least two paratopes, it can bind more than one antigen by binding identical epitopes carried on the surfaces of these antigens. By coating the pathogen, antibodies stimulate effector functions against the pathogen in cells that recognize their Fc region.
Where do antigens bind on antibodies quizlet?
The site that the antigen binds to is called the antigen binding site and this is the site that determine the specificity or what antigen the antibody will bind, thus it is the variable region.
Which antibody has two antigen binding sites?
A Typical Antibody Has Two Identical Antigen-Binding Sites Because of their two antigen-binding sites, they are described as bivalent. As long as an antigen has three or more antigenic determinants, bivalent antibody molecules can cross-link it into a large lattice (Figure 24-19).