196806-21-0Relevant articles and documents
Catalytic antibodies induced by a zwitterionic hapten
Tsumuraya, Takeshi,Takazawa, Nobuo,Tsunakawa, Atsuko,Fleck, Roman,Masamune, Satoru
, p. 3748 - 3755 (2007/10/03)
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 μM and 3.5 min-1 respectively. The catalytic rate enhancement (kcat/kun) observed for H8-1-2D5 was 1.3 × 105, 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.
