1. Catalytic antibody(abzyme) From concept to application by : Mahdi zarei M.Sc. Student ,clinical biochemistry Ferdowsi university of mashhad , iran

2. Catalytic antibody Antibody specificity Enzymes catalytic power 3. In general, synthesizing compounds that more closely resemble the transition state than the substrate itself can produce highly potent and specific inhibitors of enzymes. The inhibitory power of transition-state analogs underscores the essence of catalysis: selective binding of the transition state. Pyrrole 2-carboxylate, a transition state analog because of its trigonal geometry, is a potent inhibitor of proline racemase transition-state analogs 4. The Concept of Catalytic Antibodies (Abzymes): history: in 1948, Linus Pauling expressed the principle of enzymatic catalysis Linus Pauling proposed that compounds resembling the transition state of a catalyzed reaction should be very effective inhibitors of enzymes. These mimics are called transition-state analogs. in 1969 ,by this principle, Jenks suggested that by generating antibodies raised against a stable analogue of the TS of the reaction that one wished to catalyze, one could obtain antibodies with catalytic activity. 5. In 1985 . It was necessary to wait for another 17 years for this hypothesis to be independently demonstrated by two Californian groups, the groups of Lerner and Schultz, who for the first time obtained antibodies capable of accelerating the hydrolysis of esters. Thus, they showed that antibodies raised against phosphonates, stable analogues of the tetrahedral TS formed during the hydrolysis of esters ,could catalyze this reaction. Comparison of an ester hydrolysis tetrahedral intermediate and a phosphonate transition state mimic R OR' O OH R P OR' O O Ester hydrolysis intermediate "Transition state" mimic R OR' O HO 6. Natural catalytic antibody In 1989, Paul et al , discovered the first example of a natural Abs was an IgG (found in bronchial asthma patients) that hydrolyzes vasoactive intestinal peptide (VIP). This was followed by a discovery of IgG with DNase activity in systemic lupus erythematosus (SLE) ,and an IgG with RNase activity, also in SLE . Numerous natural catalytic Abs were detected afterwards in serum of patients with several autoimmune (AI) and viral disorders, as well as in the milk of healthy women . 7. Hapten: A small molecule that reacts with a specific antibody but cannot induce the formation of antibodies unless it is bound to a carrier protein. mimics tetrahedral intermediate in ester hydrolysis X = OH hapten X = macromolecule antigen (elicits antibody response) 8. High affinity and specific binding IgG: The most common immunoglobulin, which is distributed between the blood and extravascularfluid. The IgG is used in the formation of catalytic antibodies 9. Construction of Catalytic Antibodies A transition state analogue that mimics the transition state of the desired reaction is synthesized--called a hapten Hapten is attached to a carrier molecule capable of eliciting an antibody response--called an antigen Antigen injected into a mouse or rabbit Monoclonal antibodies (ones that bind to one region of the antigen) are isolated for that antigen The monoclonals are tested for catalytic activity( cat ELISA ,HPLC,) 10. Abzyme generation 11. There are three primary methods for eliciting catalytic antibodies currently used : Polyclonal : Polyclonal antibody production is the most primitive method and has several significant limitations. Hybridoma : Despite greater expense and a more time-consuming process, monoclonal antibody production is the method of choice . phage-display : Phage-display technology has many uses in catalytic antibody research 12. Hapten Design approach Stable transition state analog Strain-induced hapten design Bait-and-switch hapten design Reactive immunization hapten design 13. (a) Phosphonate ester as a chemically stable mimic of ester hydrolysis. (b) Transition state analog hapten1elicited antibody 48G7 that catalyzes the hydrolysis of ester2. (c) Key contacts of the 48G7 Fab- 1complex. Stable transition state analog 14. Antibody mimic of the enzyme ferrochetalase. Ferrochelatase catalyzes the insertion of Fe2+ into protoporphyrin IX as the last step in the heme biosynthetic pathway. Strain-induced hapten design N-Methylmesoporphyrin Strain-induced hapten elicited antibody 7G12 that catalyzes metalation of mesoporphyrin IX 15. This novel advancement enables electrophilic/nucleophilic and/or general acid/general base catalysis to be programmed into an antibody combining site. Bait-and-switch hapten design 16. Catalytic antibodies used in therapeutics 17. Degradation of Cocaine The hydrolysis of cocaines benzoyl ester yields two biologically inactive products . This transformation is an attractive approach to destroy cocaine prior to its absorption into the brain . Antibody catalyzed cocaine degradation Cocaine An alkaloid found in the leaves of Erythroxylon coca . Blocks removal of dopamine from a synapse in the reward pathway of the central nervous system . 18. Previous work indicated transition-state analogue using the phosphonate monoester, yielded artificial esterases with the greatest activity. Transition-State Analogue Approach 19. Coupling Transition-State Analogue to a Carrier Protein 20. Formation of Active Cocaine Degrading Antibodies 21. Other. Drug development(prodrug mechanism) Treat Cancer Treat allergy treat viral and bacterial infection (HIV ,.) 22. Thank you