Neutralizing monoclonal antibodies against ricin's enzymatic subunit interfere with protein disulfide isomerase-mediated reduction of ricin holotoxin in vitro

JM O'Hara, NJ Mantis - Journal of immunological methods, 2013 - Elsevier
The penultimate event in the intoxication of mammalian cells by ricin toxin is the reduction, in
the endoplasmic reticulum (ER), of the intermolecular disulfide bond that links ricin's
enzymatic (RTA) and binding (RTB) subunits. In this report we adapted an in vitro protein
disulfide isomerase (PDI)-mediated reduction assay to test the hypothesis that the RTA-
specific neutralizing monoclonal antibody (mAb) IB2 interferes with the liberation of RTA
from RTB. IB2 recognizes an epitope located near the interface between RTA and RTB and …