Cells expressing ricin B chain within the secretory pathway are significantly more resistant to intoxication by ricin holotoxin but not to other cytotoxins that exploit similar endocytic routes to the cytosol. Furthermore, cells expressing the related B chain of abrin are protected against both incoming abrin and ricin. These phenotypes can be correlated with the abilities of the respective B c...

abrin known as ribosome inactivating protein’s (rip) it is a high cytotoxic plant protein. high lethality and low cost and easy access to plant and seeds lead to this toxin used in crimes and terrorist acts. because obtaining purified toxins requires advanced laboratory equipment and complex procedures, so, it appears that the perpetrators of such crimes use crude extracts. as a result, remaini...

The agglutinins present in the seeds of Abrus precatorius and Ricinus communis have been separated from the toxins, abrin and ricin, and extensively purified. The procedure involves ion exchange chromatography on DEAEand CMcellulose columns, affinity chromatography on Sepharose 4B columns, and sucrose gradient centrifugation. The purified agglutinins which possessed almost no toxic activity wer...

As the possible mechanisms of inhibition of protein biosynthesis, it was demonstrated that the toxic proteins abrin and ricin cause the degradation of polyribosomes of rat liver or Ehrlich ascites tumor cells. Abrin and ricin have no direct effect on the structural and functional integrity of polyribosomes but act indirectly by increasing the RNase activity in the postmicrosomal supernatant fra...

Synthetic biotinylated RNA substrates were cleaved by the combined actions of ricin holotoxin and a chemical agent, N,N'-dimethylethylenediamine. The annealing of the product with a ruthenylated oligodeoxynucleotide resulted in the capture of ruthenium chelate onto magnetic beads, enabling the electrochemiluminescence (ECL)-based detection of RNA N-glycosidase activities of toxins. ECL immunoas...

The toxicity of abrin, modeccin, and ricin to Vero cells was maximal at neutral and slightly alkaline pH, and it was strongly reduced at pH 6.0 and below. Diphtheria toxin was most toxic at low pH. Binding and endocytosis of abrin, modeccin, and ricin did not vary much within the pH range tested. High concentrations of the carboxylic ionophore Br-X-537A, protected against all four toxins. Combi...

Abrin and ricin are highly toxic and lethal proteins which have the potential to be used as bioterrorism agents.Labrine and ricinine, molecular biomarkers for abrin and ricin, serve as useful biomarkers in assessing exposure and contamination.In this study, we developed a method for the quantitation of L-abrine and ricinine spiked into four food types: ground beef, chicken breast, hot dogs, and...