Antibodies are therefore key elements in all vertebrate immune systems.
That is the first point. The second point is that we now know that enzymes work the way they do mostly because they bind transition state entities in chemical reactions, this binding lowering the energy barrier to the transition state, and thereby increasing the reaction rate many-fold. Which provokes the notion that it might somehow be possible to use the high specificity of anti- bodies in catalysis. And the notion is correct. Lysine is one of the amino acids found in biological systems.