Antibodies
619
- Antibodies (Immunoglobulins)
- Main component of the humoral response of the adaptive immune system
- Y-shaped proteins
- Recognize and bind antigens
- Binding to antigens attracts innate immune cells to phagocytose and destroy the pathogen
- Produced by B cells
- Each B cell makes a single type of antibody or immunoglobulin, which can recognize and bind to a specific antigen
- Can exist as membrane-bound cell receptors or independently in circulation
- Structure of an antibody
- Two identical heavy chains and light chains
- Connected by disulfide bonds
- Both heavy and light chain involved in forming:
- Constant region
- Does not bind antigens
- Signals to other cells (eg, phagocytes) and proteins to destroy antigen bound at other end
- Variable region
- Binds antigen
- Unique amino acid structure of this region determines specificity of antibody
- Constant region
- Two identical heavy chains and light chains