• 1 February 1974
    • journal article
    • Vol. 26  (2) , 303-10
Abstract
Plasmin digestion of rabbit IgG after pretreatment at low pH yields a fragment (Facb) which has lost the CH3 domain. A study of the biological activity of this fragment is described and the following conclusions are drawn: (1) Facb possesses the same antigen-combining capacity as the whole antibody; (2) C1 fixation is normal; (3) The capacity to sensitize target cells to lysis by cytotoxic K cells is lost; (4) Facb—antigen complexes are unable competitively to inhibit phagocytosis of sensitized bacteria by neutrophils.