Ricin: Difference between revisions
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{{STRUCTURE_2r3d| PDB=2r3d | SIZE=400| SCENE= |right|CAPTION=Castor bean ricin | {{STRUCTURE_2r3d| PDB=2r3d | SIZE=400| SCENE= |right|CAPTION=Castor bean ricin A chain with acetamide and sulfate, [[2r3d]] }} | ||
==Introduction== | ==Introduction== | ||
'''Ricin''' is a potent cytotoxin that is synthesized in the endosperm cells of maturing castor oil plant ( | '''Ricin''' is a potent cytotoxin that is synthesized in the endosperm cells of maturing seeds of the castor oil plant (''Ricinus communis'')<ref name="lord">PMID: 8119491</ref>. Ricin belongs to a small multi-gene family<ref name="montfort">PMID: 3558397</ref> that is composed of eight members. Ricin is classified as a type II heterodimeric [[Ribosome]] Inactivatiing protein<ref name="lord" />. | ||
==Structure== | ==Structure== | ||
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==Physiology== | ==Physiology== | ||
The mechanism deployed by Ricin to gain entry to a host cell uses the heterogenic properties given to the toxin. Firstly the toxin arranges itself in such a way where its B chain can easily interact with the host cells receptors, and once acknowledgement happens, the B chain can fascilitate transport of the A chain into the cytoplasm<ref name="montfort" />. This association between the A and B chain is essential for toxicity<ref name="montfort" /> without it the Ricin would not be able to gain access to the cells organelles rendering it useless. Once the A chain gains entry into the cytosol its mechanism for attack of the [[Ribosome|ribosome]] is depurination of a single endenosine residue in large RNA of the [[Large Ribosomal Subunit of Haloarcula|large ribosomal subunit]]<ref name="rapak" />, which in humans is called the 28S ribosomal RNA because of its sedimentation properties during ultracentrifugation. | The mechanism deployed by Ricin to gain entry to a host cell uses the heterogenic properties given to the toxin. Firstly the toxin arranges itself in such a way where its B chain can easily interact with the host cells receptors, and once acknowledgement happens, the B chain can fascilitate transport of the A chain into the cytoplasm<ref name="montfort" />. This association between the A and B chain is essential for toxicity<ref name="montfort" /> without it the Ricin would not be able to gain access to the cells organelles rendering it useless. Once the A chain gains entry into the cytosol its mechanism for attack of the [[Ribosome|ribosome]] is depurination of a single endenosine residue in large RNA of the [[Large Ribosomal Subunit of Haloarcula|large ribosomal subunit]]<ref name="rapak" />, which in humans is called the 28S ribosomal RNA because of its sedimentation properties during ultracentrifugation. Depurination of the ribosomal RNA by the poison in turn results in the inhibition of protein synthesis. | ||
==3D structures of ricin== | ==3D structures of ricin== | ||
