3825 Restrictocin (Aspergillus restrictus) Restrictocin is a protein mycotoxin produced by the fungi Aspergillus giganteus and Aspergillus restrictus. It is a highly specific ribotoxin and inhibits protein synthesis by cleaving the 28S RNA of eukaryotic ribosomes. (A3081, A3084) 1406-72-0 19595.00499999999 Clear solution. >10 mg/mL Oral, dermal, inhalation, and parenteral (contaminated drugs). (A3101) Restrictocin is a highly specific ribotoxin that inhibits protein synthesis by cleaving a single phosphodiester bond in the sarcin/ricin loop (SRL) of the 23S−28S rRNA of eukaryotic ribosomes. The sequence around this cleavage site is a binding site for elongation factors, and is conserved in all cytoplasmic ribosomes. In order to cleave this site, restrictocin binds to the rRNA by forming an electrostatic complex using specific residues on its active site face. This cleavage prevents the binding of elongation factors to the ribosome, halts protein synthesis, and eventually leads to apoptotic cell death. (A3081, A3082, A3083) Free toxin may be removed by opsonization via the reticuloendothelial system (primarily the liver and kidneys) or it may be degraded through cellular internalization via the lysosomes. Lysosomes are membrane-enclosed organelles that contain an array of digestive enzymes, including several proteases. No indication of carcinogenicity to humans (not listed by IARC). Restrictocin is a protein mycotoxin produced by the fungi Aspergillus giganteus and Aspergillus restrictus. (A3081) Restrictocin is a cytotoxic ribotoxin, causing cell death by inactivating eukaryotic ribosomes. (A3084) 2010-05-25T21:38:23Z 2014-12-24T20:26:31Z P67876 1AQZ Aspergillus restrictus true Exogenous Liquid 1aqz_bio_r_500.jpg image/jpeg 35315 2014-10-14T18:14:24Z BSEQ0008534