Table 1.

Characteristics of the isolated anti-ricin antibodies.

Antibody	Vaccine a	Binding b	ED50 (ng/mL) c	kon (1/Ms)	koff (1/s)	KD (nM)
MH1	subunit	RTA	200 d	9 × 104	<1 × 10−7	<0.001
MH2	subunit	RTB	5200	18 × 104	1 × 10−5	0.6
MH36	holotoxin	RTA	27,000	11 × 104	<1 × 10−7	<0.001
MH49	holotoxin	RTA	1200	7 × 104	<1 × 10−7	<0.001
MH67	holotoxin	RTA	52,000	9 × 104	8 × 10−4	9.0
MH73	subunit	RTB	11,000	11 × 104	<1 × 10−7	<0.001
MH74	subunit	RTA	83,000 d	15 × 104	7 × 10−3	45
MH75	subunit	RTB	150 d	35 × 104	<1 × 10−7	<0.001
MH76	subunit	RTB	10,500	11 × 104	3 × 10−4	3.0
MH77	subunit	RTB	500	17 × 104	1 × 10−7	0.001

^a The vaccine used to immunize the animal from which the antibody was isolated. ^b Binding of each antibody to ricin subunits was determined by enzyme linked immunosorbent assay (ELISA), except for MH73, which was tested by Octet. ^c The antibody concentration needed to neutralize 50% (ED₅₀) of ricin activity in vitro. ^d Values taken from our previous study [27] are presented here for comparison.