BIO 361 Lecture Notes - Lecture 18: B-Cell Linker, Sigd, Lymphatic System
10 Jul 2016
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Document Summary
Structurally relevant view of folding in the fab and fc ends. The iga and igm molecules have accessory chains called j-chains (j for joining) that joins hetero- tetrameric subunits, and are not involved in either recognition of cells or antigens. There are 3 constant regions per igg molecule that gives rise to a subdivision of igg molecule, so that there are iggs that have different constant regions from their relatives. Those differences are not associated primarily with differences in antigen recognition. But the variable regions of the light and heavy chains combine to increase the capacity of the hetero-tetramer to recognize all sorts of molecules. Antibodies can be chopped up with proteases, commonly papain and pepsin. Papain cleaves antibodies to 2 individual fab portions (one antigen binding site each) and one fc fragment. Fab portions alone can by the body. bind to antigens but are not effective in being cleared.
