BEH. 462/3.962J Molecular Principles of Biomaterials Spring 2003 Antibody fragmentation enzymes Papain cleavag Pepsin Cleavage -SS-N -S.S. Flab)2 Fragment Fe Subfragments FAb framer Fe Subfragment Utility of antibody framer on Lack Fc region; reduced binding to phagocytic FcR-bearing macrophages and other phagocytes ou Reduced immunogenicity for non-humanized antibodies o FAb allows production of monovalent binding molecule Bivalent binding can trigger unwanted signaling cascades(e.g EGFR) a Unique chemical sites introduced at opened hinge region in FAb or F(Ab) Maleimide g- group MAL MAL MAL PEG surface Maleimide reaction with thiol creates stable thioether linkage onsoUrceofgraphichttp://www.nature.com/nrd/journal/v1/n7/slideshow/nrd838bx1.html Lecture 17-Drug targeting 3 of 7BEH.462/3.962J Molecular Principles of Biomaterials Spring 2003 FAb fragments Antibody fragmentation enzymes: papain papain Papain cleavage -S-S- (Pierce Chemical Co.) ƒ Utility of antibody fragments: o Lack Fc region; reduced binding to phagocytic FcR-bearing macrophages and other phagocytes o Reduced immunogenicity for non-humanized antibodies o FAb allows production of monovalent binding molecule ƒ Bivalent binding can trigger unwanted signaling cascades (e.g. EGFR) o Unique chemical sites introduced at opened hinge region in FAb’ or F(Ab’)2 HS SH Maleimide Eng-group B B + Couple via QuickTime™ and a Graphics decompressor are needed to see this picture. streptavidin to device -SH MAL PEG surface layer MAL MAL QuickTime™ and a Graphics decompressor are needed to see this picture. ƒ Maleimide reaction with thiol creates stable thioether linkage: o Source of graphic: http://www.nature.com/nrd/journal/v1/n7/slideshow/nrd838_bx1.html Lecture 17 – Drug targeting 3 of 7