An active immunization approach to generate protective catalytic antibodies

Abstract

We report that mice immunized with a phosphate immunogen produced polyclonal catalytic antibodies (PCAbs) that catalysed the hydrolysis of carbaryl, a widely used broad-spectrum carbamate insecticide that exerts toxic effects in animals and humans. The reaction catalysed by the PCAbs (IgGs) obeyed Michaelis-Menten kinetics in vitro with the following values at pH 8.0 and 25 degrees C: K(m) approximately 8.0 microM, k(cat)=4.8x10(-3)-5.8x10(-1), k(cat)/k(non-cat)=5.6x10(1)-6.8x10(3) (where k(non-cat) is the rate constant of the reaction in the absence of added catalyst). The PCAbs were also active in whole sera under physiological conditions in vitro. The PCAbs induced in vivo were also active in vivo, as immunization with the phosphate immunogen decreased the mouse blood concentration of carbaryl. To our knowledge, this is the first report demonstrating that active immunization generates antibodies possessing therapeutic catalytic function in vivo. We propose that active immunization schemes that induce enzymically active antibodies may provide a highly specific therapeutic approach for degrading toxic substances.

Natural Antibodies Produced in Vaccinated Patients and COVID-19 Convalescents Hydrolyze Recombinant RBD and Nucleocapsid (N) Proteins

“…However, this activity may have significant immunological effects in vivo, given the long half-life of antibodies and high titers of circulating antibodies [37][38][39], and the amount of viral proteins relative to antibodies is relatively low. In addition, a low activity level is also characteristic of other proteolytically active antibodies [40][41][42][43].…”

“…Figure 3A- proteins relative to antibodies is relatively low. In addition, a low activity level is also characteristic of other proteolytically active antibodies [40][41][42][43].…”