Catalytic polyclonal antibodies.

The production and characterization of rabbit polyclonal antibodies that catalyze the hydrolysis of trityl protecting groups is described. The catalytic activity increased throughout the immunization regimen, exhibiting a later and steeper rise than the simple hapten-specific antibody titer. The catalytic polyclonal antibodies displayed saturation behavior, consistent with classic Michaelis-Menton kinetics. An apparent catalytic rate enhancement (kcat/kuncat) of 125 and a Km of 31 microM were measured for the polyclonal sample. Inhibition studies indicated that 12% of the antibodies either binds the hapten or is a catalyst. Analyzing polyclonal antibodies for catalytic activity is proposed as a substantially faster, more cost effective and more general way to screen new hapten designs for their relative abilities to produce antibodies with catalytic activity.