( ( One antibody ) ( ( ( is specifically ) ( designed ( to ( attack ( one antigen ) ) ) ) ) . ) )
(ROOT (S (NP (CD One) (NN antibody)) (VP (VBZ is) (ADVP (RB specifically)) (VP (VBN designed) (S (VP (TO to) (VP (VB attack) (NP (CD one) (NN antigen))))))) (. .)))
One antibody is specifically designed to attack one antigen.
(ROOT (S (NP (DT An) (NN antibody)) (VP (MD can) (VP (VB match) (NP (NP (CD one) (NNS types)) (PP (IN of) (NP (NNS antigens)))))) (. .)))