Studies on propylamine transfer activity in anti-AdoDATO antibodies

Summary Based on a structural similarity to the transition state of a propylamine transfer reaction involved in polyamine biosynthesis, Sadenosyl-(5)-1,8-diamino-3-thiooctane (AdoDATO), the most potent inhibitor of spermidine synthases, was used as a hapten for mice immunization. From immunized mice sera, the IgG fractions were purified by means of affinity (protein A/G) chromatography. Sera and purified polyclonal antibodies from several mice were found to exert spermidine synthase-like activity. Moreover, by means means of hybridoma technology, 19 anti-AdoDATO hybridoma clones have been screened for propylamine transfer activity and at least 6 were found to produce catalytic antibodies. These findings indicate the presence in the sera of active spermidine synthase-like catalytic antibodies. The reported results for the first time evidence the feasibility of preparation of N-alkylating antibodies, widening the biotechnological perspectives of antibodies as biocatalysts.Abbreviations AdoDATO S-adenosyl-(5)-1,8-diaminothiooctane - TSA Transition state analog - decAdoMet S-adenosyl-(5)-3-methylthiopropylamine (decarboxylated adenosylmethionine) - KLH keyhole limpet hemocyanin - NMR nuclear magnetic resonance - BSA bovine serum albumine - WSC 1-ethyl-3-(dimethylaminopropyl)carbodiimide (water-soluble carbodiimide) - PBS phosphate buffer saline - OPD orthodiphenylenediamine - TCA trichloroacetic acid - SDS-PAGE sodium duodecylsulphate-polyacrylamide gel electrophoresis - SN2 bimolecular nucleophilic substitution; abzyme catalytic antibody - IgG immunoglobulin G