• Archives of Pharmacal Research
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• v.17 no.6
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• pp.452-457
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• 1994

The water soluble long-chain crosslinker, sulfo-succinimidyl-6-[3'-(2-pyridyldithio)-propion-amido]hexanoate (S-LC-SPDP) was used to prepare ricin A chain (RAT) immunotoxins constructed with whole igG and Fab fragments of the anti-common acute lymphoblastic leukemiz antigen (CALLA)monoclonal antibody. In this study, a) S-LC-SPDP modification efficiencies immunoreactivity and cytotoxicity of immunotoxins constructed were examined. IgG-RTA and Fab-RTA immunotoxins were prepared with 67.3% and 57.0% conjugation yields, respectively. These long spacer intemolecular linked immunotoxins were selectively immunoreactive and to antigen K562 cells. Both IgG-RAT and Fab-RAT immunotoxins were 210-and 45-fold more active than intavt RAT in vitro, respectively.