Antibody bait and switch catalysis: a survey of antigens capable of inducing abzymes with acyl-transfer properties
摘要:
Antibodies have been shown to catalyze acyl-transfer reactions. Various antigens have been applied to these hydrolytic reactions, but typically all encompass the same theme of incorporating a monoanionic phosphonate/phosphonamidate. To expand the scope and capabilities of these abzymes, we have directed our attention toward new strategies in antigen design. One method, which we have termed ''bait and switch'' catalysis, uses haptens to elicit amino acid(s) within the binding pocket of an antibody that can accelerate hydrolysis. We reported initial success of this methodology utilizing the cationic hapten 1 for obtaining abzymes that hydrolyzed benzoate ester 6. In addition, we showed how the structurally identical but neutral hapten 2 was unable to induce catalytic antibodies. To further identify those factors critical in the generation of hydrolytic abzymes via our bait and switch methodology, we have (1) designed and synthesized three new homologues of 1 in which we have varied the type of charge/no charge and its location, (2) screened and identified catalytic antibodies from these antigens, (3) determined affinity constants of a number of these monoclonal antibodies (catalytic and noncatalytic) for their respective haptens and possible substrates (ester/amide), (4) performed steady-state kinetics, inducing a pH-rate profile on one of these abzymes, and (5) used chemical modifying reagents to identify which amino acid residue(s) are involved in these catalytic processes.
Antibody bait and switch catalysis: a survey of antigens capable of inducing abzymes with acyl-transfer properties
摘要:
Antibodies have been shown to catalyze acyl-transfer reactions. Various antigens have been applied to these hydrolytic reactions, but typically all encompass the same theme of incorporating a monoanionic phosphonate/phosphonamidate. To expand the scope and capabilities of these abzymes, we have directed our attention toward new strategies in antigen design. One method, which we have termed ''bait and switch'' catalysis, uses haptens to elicit amino acid(s) within the binding pocket of an antibody that can accelerate hydrolysis. We reported initial success of this methodology utilizing the cationic hapten 1 for obtaining abzymes that hydrolyzed benzoate ester 6. In addition, we showed how the structurally identical but neutral hapten 2 was unable to induce catalytic antibodies. To further identify those factors critical in the generation of hydrolytic abzymes via our bait and switch methodology, we have (1) designed and synthesized three new homologues of 1 in which we have varied the type of charge/no charge and its location, (2) screened and identified catalytic antibodies from these antigens, (3) determined affinity constants of a number of these monoclonal antibodies (catalytic and noncatalytic) for their respective haptens and possible substrates (ester/amide), (4) performed steady-state kinetics, inducing a pH-rate profile on one of these abzymes, and (5) used chemical modifying reagents to identify which amino acid residue(s) are involved in these catalytic processes.
Molecules with antibody combining sites that catalyze hydrolysis
申请人:Scripps Clinic and Research Foundation
公开号:US05187086A1
公开(公告)日:1993-02-16
An antibody molecule or molecule containing antibody combining site portions (catalytic molecule) that catalytically hydrolyzes a preselected carboxylic acid amide or ester bond of a reactant ligand, methods of making and using the catalytic molecule, and cells that produce those molecules are disclosed. The catalytic molecules bind to a reactant ligand containing the bond to be hydrolyzed and also to a haptenic ligand. The haptenic ligand is structurally analogous to the reactant ligand and contains a tetrahedral carbon atom that is bonded to a hydroxyl group and to a saturated carbon atom at a position in the haptenic ligand that corresponds to position of the carbonyl group and its bonded heteroatom of the reactant ligand. The haptenic ligand also contains a group that bears an ionic charge in aqueous solution at physiological pH values that is not present at a corresponding position of the reactant ligand. The ionic charge-bearing group is located in the hapten within 7 .ANG.ngstroms of the tetrahedral carbon atom.
作者:Nicholas D. J. Yates、Saeed Akkad、Amanda Noble、Tessa Keenan、Natasha E. Hatton、Nathalie Signoret、Martin A. Fascione
DOI:10.1039/d2gc02292c
日期:——
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