METHOD FOR SPECIFIC COVALENT COUPLING OF ANTIBODY USING A PHOTOACTIVABLE PROTEIN G VARIANT

摘要

PURPOSE: A protein G variant containing Fc binding domain is provided to form covalent bond with an antibody by UV and enable antibody fixation. CONSTITUTION: A protein G variant in which cystein is modified is denoted by formula Tx-Ly-(cystein induced G-Fc binding domain)n - Qz. The cystein modified Fc binding domain has 21Val, 29Ala or 47Asp amino acid which is substituted with cystein. The protein G variant additionally binds UV cross linder complex which selectively reacts to thiol group. The UV cross linker complex comprises UV cross linker, side linker and reaction group. The UV cross linker is benzophenone, aryl azide or their derivatives. The reaction group is maleimide or haloacetyl.