• Toxicological Research
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• v.11 no.2
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• pp.193-197
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• 1995

Antibody-toxin conjugates, termed immunotoxins, are currently being evaluated as potential new anticancer agents and one of the most extensively studied toxins for construction of immunotoxin is ricin which exists in the seeds of castor bean, Ricinus communis. Another toxic lectin from castor bean is RCA (Ricinus communis agglutinin). Both toxins are very homologous. We reported the puriffcation procedure and biological properties of ricin from the Korean castor bean in another place and here we report those of RCA. The purified RCA shows three bands on denatured SDS PAGE while ricin shows two bands. On cultured $K_{562}$ cells ricin and RCA both inhibit the multiplication of cells extensively. $30{\mu}g/ml$ of ricin shows 73% of inhibition rate at day 4 compared to 68% in same condition of RCA. The inhibition of multiplication of cells are directly proportional to the concentration of toxins and the incubation period. In every case ricin was more toxic than RCA. The $LD_{50}$ dose of ricin on ICR mice was 60 ng at day 3 but that of RCA was $10{\mu}g$.

• Journal of Life Science
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• v.11 no.2
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• pp.111-120
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• 2001

The pathological aspects of purified ricin from the seeds of the castor oil plant, Ricinus communis, were examined, using light and transmission electron microscopy. ICR mice were exposed to ricin by peritoneal injection with 100 ng/1 $m\ell$ PBS(pH 7.0) mouse and histological observations on the liver, spleen, thymus, lung and heart were carried out at intervals up to 48 h after exposures. All the organs examined were damaged by ricin. Among the organs, the spleen and thymus; immune organs were the most sensitive to ricin, whereas the effect delayed in the liver, lung and heart. Furthermore, the immune cells in each organ were the most sensitive to ricin. Accordingly, the effect of ricin on the organs seems to be affected by the immune cells existed in each organ, In each organ, the immune cells showed apoptotic changes, while the capillary endothelial and parenchymal cells showed necrotic changes.

• Bulletin of the Korean Chemical Society
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• v.32 no.12
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• pp.4253-4257
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• 2011

Sodium dodecyl sulfate-capillary gel electrophoresis (SDS-CGE) and capillary isoelectric focusing (CIEF) were employed to characterize and compare ricin E purified from the small grain seeds of Ricinus communis with ricin D isoform. During the purification of ricin E using ion-exchange and size-exclusion chromatography, SDS-CGE was found to be useful for monitoring the efficiencies of purification steps. SDS-CGE showed that the molecular size of ricin E was not significantly different from that of ricin D, which was confirmed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. CIEF was useful for discriminating ricin E from ricin D based on their isoelectric points (pI). The pI values of ricin E and D were 8.6-8.8 and 7.0-7.4, respectively. This study demonstrates the usefulness of SDS-CGE and CIEF for the characterization of ricin toxins.

• Journal of the Korea Institute of Military Science and Technology
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• v.27 no.2
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• pp.304-310
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• 2024

Ricin is a highly toxic protein which is produced in the seeds of the castor oil plant. Ricin toxin A chain has ribosomal RNA N-glycosylase activity that irreversibly hydrolyses the N-glycosidic bond of the adenine residue at position 4324 within the 28S rRNA. In this study, we developed non-toxic recombinant ricin vaccine(R51) in E. coli expression system, and evaluated efficacy of the R51 according to adjuvants. When the R51 was administered using aluminum hydroxide as an adjuvant, the vaccine efficacy was higher than that of TLR agonists or aluminum phosphate. Because it is time-consuming to administer the vaccine three times at three-week intervals, we investigated the survival rate and antibody titer of mice according to the change of time interval of vaccination. Interestingly, there was no difference in survival rate and antibody titer when R51 was administered at 0, 1, and 3 weeks or 0, 2, and 4 weeks compared to when administered at 0, 3, and 6 weeks. Therefore, the developed R51 vaccine is promising to protect soldiers from Ricin attack.

• Korean Journal of Food Science and Technology
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• v.11 no.3
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• pp.206-208
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• 1979

• Journal of Environmental Science International
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• v.6 no.1
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• pp.53-60
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• 1997

The toxicity of purified ricln from Ricinus communis to rats was examined by histological and histochemical methods. Sprague-Dawley rats were injected intraperitoneally with 75$\mu\textrm{g}$/kg body weight of ricin and were sacrified at itntervals of 6, 24, 48 and 120 hours after injectoon. The major morphological changes, such as cloudy swelling, hydropic degeneration, necrosis, fatty change, blood congestion, increase of Kupffer cells in number and extension of sinusoids, were obvious in the liver of experimental group. These morphological changes of hepatic cells were mainly observed in both the periportal and midlobular region of hepatic lobule. The extension of sinusoids was obvious in the controlobular region. And glycogen dlstrlbution of hepatic cells tended to decrease in the same region showing morphlogical changes as compared with the control group.

• 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.

• Archives of Pharmacal Research
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• v.22 no.5
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• pp.459-463
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• 1999

The effects of the hindered and non-hindered water soluble long-chain disulfide bonds on the stability and cytotoxicity of the ricin A chain (RTA) immunotoxin were examined. The RTA immunotoxins were prepared with the Fab fragments of anti-common acute lymphoblastic leukemia antigen (CALLA) monoclonal antibody (Fab-RTA) using sulfosuccinimidyl-6-[(-methyl-(-2-pyridyldithio)toluamido]toluamido]hexanoate (S-LC-SMPT) and sulfosuccinimidyl-6-[3-(2-pyridyldithio-propionamido]hexanoate (S-LC-SPDP). The prepared Fab-RTA immunotoxins were evaluated for their conjugation yield, immunoreactivity, thermal and disulfide bond stability and cytotoxicity. The conjugation yield of the Fab-RTA immunotoxin from the water soluble long chain crosslinking agents, S-LC-SMPT and S-LC-SPDP, were comparable. Both Fab-RTA immunotoxins exhibited a similar immunoreactivity and thermal stability in aqueous solution. However, S-LC-SMPT -mediated Fab-RTA, sterically hindered, showed an enhanced disulfide bond stability in vitro over S-LC-SPDP mediated one. In the cytotoxicity against antigenic cell Daudi, the S-LC-SMPT -mediated RTA immunotoxin maintained a comparable cytotoxicity, compared with S-LC-SPDP mediated Fab-RTA immunotoxin.

• The Zoological Society Korea : Newsletter
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• v.12 no.2
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• pp.90.2-90
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• 1995

• Proceedings of the Zoological Society Korea Conference
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• 1995.10b
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• pp.216.2-216
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• 1995