Cleaving its hinge with papain separates its Fc [eff-cee] and Fab [eff-ay-bee] portions.  
Cleaving its hinge with papain separates its Fc [eff-cee] and Fab [eff-ay-bee] portions.  Its structure was established by Gerald Edelman and Rodney Porter, who found a characteristic beta fold in each of its 8 constant domains.  The A type is found in saliva and milk, the G type activates macrophages, and the M type is made by B cells early in immune response.  Consisting of two heavy chains and two kappa or lambda light chains and variable regions, FTP, name this immune protein produced in response to the presence of a specific antigen.
Cleaving its hinge with papain separates its Fc [eff-cee] and Fab [eff-ay-bee] portions.  
antibody or immunoglobulin