Antibodies are major components of humoral immunity. IgG is the main type of antibody found in blood and extracellular fluid, allowing it to control infection of body tissues. By binding many kinds of pathogens such as viruses, bacteria, and fungi, IgG protects the body from infection. IgG antibodies are generated following class switching and maturation of the antibody response, thus they participate predominantly in the secondary immune response. gG is secreted as a monomer that is small in size allowing it to easily perfuse tissues. It is the only antibody isotype that has receptors to facilitate passage through the human placenta, thereby providing protection to the fetus in utero. Along with IgA secreted in the breast milk, residual IgG absorbed through the placenta provides the neonate with humoral immunity before its own immune system develops. Colostrum contains a high percentage of IgG, especially bovine colostrum. In individuals with prior immunity to a pathogen, IgG appears about 24–48 hours after antigenic stimulation. IgG antibodies can prevent IgE mediated anaphylaxis by intercepting a specific antigen before it binds to mast cell–associated IgE. Consequently, IgG antibodies block systemic anaphylaxis induced by small quantities of antigen but can mediate systemic anaphylaxis induced by larger quantities. Here you can see a crystal structure of IgG1 Fc fragment (PDB code: 8A48)
#molecularart ... #immolecular ... #antibody ... #igg ... #response ... #xray
Structure rendered with @proteinimaging and depicted with @corelphotopaint
#molecularart ... #immolecular ... #antibody ... #igg ... #response ... #xray
Structure rendered with @proteinimaging and depicted with @corelphotopaint
