IMM340H1 Lecture Notes - Lecture 4: Disulfide, Epitope, Immunoglobulin Domain
Document Summary
Only when the 2 chains come together can it bind to an antibody. The bond holding the kght chain to the heavy chains are called disulphide bonds, and theres disulphide bonds holding the heavy chaisn together. The hinge region is subject to proteolytic attack. They cleave above the disulphide bond, so it liberates 2. Pepsin cuts in a different place, pepsin cuts below the disulphide bonds, so the fragments released are called pepsi(cid:374) c f(cid:396)ag(cid:373)e(cid:374)ts, (cid:271)ut the fa(cid:271)"s a(cid:396)e still li(cid:374)ked (cid:271)y the disulphie bonds that hold the heavy chains together. When we loo at antibody moleculs that are binding antigens by electron microscopy, it became clear that antibody antigen complexes looked different depending how many antibody molecules are in a complex that binds to an antigen. The important thing about this is that it formally proves that the angles between the 2 arms of the igg molecule has flexibility, they can move.
