Immunological studies of catechol methyltransferase from the yeast Candida tropicalis

Immunization of rabbits with purified catechol methyltransferase from Candida tropicalis yielded a potent antiserum. Ouchterlony double diffusion analysis showed a single precipitin line. There was no cross reactivity with the catechol methyltransferase from rat and bovine liver. Specific antigen-antibody interaction was demonstrated by a potent inhibitory effect of the antibody on the yeast enzyme. Immunological titration and quantitative precipitin reaction of the enzyme showed that the maximum amount of precipitable complex occurred at the equivalence point where enzyme activity was completely inhibited.