Catalytic Antibodies for Prophylaxis/Treatment of Cyanide Poisoning
Abstract
Hydrogen cyanide reacts with a,b-unsaturated ketones (enones) to form stable compounds under physiological conditions (temperature, pH). Rate enhancement by the presence of a suitable catalyst would permit the use of enones as prophylactic drugs for cyanide exposure. An enone drug was synthesized and shown to have low acute toxicity. A transition state analog for the reaction of the drug with cyanide was designed, synthesized, and conjugated to protein. The conjugate was used to produce over 300 hybridomas producing antibodies that bind the TSA. Four monoclonal antibodies significantly enhanced the reaction rate, as shown by HPLC analysis of the product. The TSA markedly diminished the reaction velocity, indicating the involvement of the antibody binding site in the observed enhancement. Kinetic analysis of one antibody gave values of Kenone and KKCN of 51 JIM and 9.6 mM, respectively, with a value of kcat of 2.33 h-1. Computer simulations showed that (among other combinations) reducing Km for both reactants by a factor of 1 0 and increasing kcat by a factor of 600 would produce a practical antibody for cyanide detoxification. To accomplish this, we recommend an approach using modified TSAs to produce improved antibodies combined with protein engineering techniques to further enhance activity. Cyanide, Prophylaxis, Antibody, Catalysis, Enone, Michael addition.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 28, 1993
- Accession Number
- ADB176814
Entities
People
- C. E. Cook
- Carol C. Whisnant
- David A. B. Miller
- Donna Allen
Organizations
- RTI International