Gudrun Scharte

Production and Characterization of Monoclonal Antibodies Against Urea Derivatives

A panel of monoclonal antibodies was generated against the ureabased haptenN-(2-N-chloroacetylaminobenzyl)-N′-4-chlorophenylurea as a tool for building up sensitive immune assays to detect urea derivatives and to screen them for catalytic antibodies (Abs). Eleven hybridomas were obtained that produced Abs reactive to the hapten. All Abs were of IgG class. Crossreactivities of the Abs to different haptens were examined, especially to a possible transition-state analog. Only four of the hybridomas (R2-DA10/F7, R2-GE7/H2, R2-HC2/A5, R2-HD6/F7) produced Abs crossreactive with the transition-state analog. From the 11 hybridomas, hybridoma B76-BF5 was chosen for further characterization. Compared to the other Abs, B76-BF5 showed the strongest binding and had a rather restricted specificity. These Abs could be used to build up a sensitive enzyme immunoassay for the detection of the hapten. All Abs were screened for crossreactivity with the pesticides monuron and diuron. No reactivity could be detected. In addition, the nucleotide sequences of the variable light and heavy chain genes of the similarly reactive Abs B76-BF5, B76-BB3, R2-DA10/F7, and R2-GA6/G3 were determined to clarify whether structure and binding specificity of these Abs showed any correlation.

Monoclonal anti-diuron antibodies prevent inhibition of photosynthesis by diuron

Two monoclonal anti‐diuron antibodies were generated that bind to diuron with an extremely low equilibrium dissociation constant. The antibodies prevented and restored in vitro and in vivo the diuron‐dependent inhibition of photosynthesis. In isolated thylakoids prepared from spinach leaves (Spinacia oleracea L.) the diuron‐inhibited Hill reaction was reconstituted immediately after the addition of the monoclonal antibodies. The antibodies also restored the diuron‐dependent inhibition of the photosynthetic oxygen evolution of the cell wall‐deficient mutant cw15 of the green alga Chlamydomonas reinhardtii Dangeard.