Catalytic antibodies induced by a zwitterionic hapten

Chemistry. 2001 Sep 3;7(17):3748-55. doi: 10.1002/1521-3765(20010903)7:17<3748::aid-chem3748>3.0.co;2-g.

Abstract

A zwitterionic hapten 4 featuring both positively and negatively charged functional groups was designed and synthesized with the goal of generating catalytic antibodies for the hydrolysis of ester 6 and amide 7. Of the 36 monoclonal antibodies specific to BSA-4 (bovine serum albumin) that were isolated, six accelerated the hydrolysis of 6. Two catalytic antibodies with distinctively different and representative kinetic behaviors were selected for detailed kinetic studies. Whereas H8-2-6F11 showed burst kinetic behavior, which can be attributed to the formation of an acyl intermediate, H8-1-2D5 did not, but it did exhibit high multiple turnover activity. The rate of hydrolysis of 6 catalyzed by H8-1-2D5 followed Michaelis-Menten kinetics; the apparent values of the Michaelis-Menten constant Km and the catalytic constant kcat were 488 microM and 3.5 min(-1), respectively. The catalytic rate enhancement (kcat/kun) observed for H8-1-2D5 was 1.3 x 10(5), which is approximately two orders of magnitude greater than those for monofunctional haptens. Thus H8-1-2D5 compares well in catalytic activity with antibodies isolated by a related approach called heterologous immunization.

MeSH terms

  • Amides / metabolism
  • Animals
  • Antibodies, Catalytic / biosynthesis
  • Antibodies, Catalytic / chemistry*
  • Binding Sites, Antibody
  • Esters / metabolism
  • Haptens / administration & dosage
  • Haptens / immunology*
  • Hydrolysis
  • Ions
  • Kinetics
  • Mice
  • Models, Chemical
  • Structure-Activity Relationship

Substances

  • Amides
  • Antibodies, Catalytic
  • Esters
  • Haptens
  • Ions