Ricin
Ricin is a potent protein toxin found in castor bean seeds. Its enzymatic subunit damages ribosomes, stopping protein synthesis and killing cells.
Ricin A chain: The enzymatic subunit of ricin that damages ribosomal RNA and inhibits protein synthesis. It removes a specific adenine from ribosomal RNA, disabling the ribosome.
Castor bean: The seed of the castor oil plant, Ricinus communis, which contains ricin. Ricin occurs naturally in the seed, alongside castor oil.
Ricin vaccine: An experimental vaccine designed to induce immunity against ricin exposure. Vaccine research seeks protection against ricin while accounting for the toxin’s danger.
Ricin poisoning: Illness caused by exposure to ricin, with effects that depend on the route and amount of exposure. This is the human consequence of ricin entering the body.
Abrin: A potent ribosome-inactivating protein found in the seeds of Abrus precatorius. Abrin resembles ricin in its cellular target but comes from a different plant.
Ricin B chain: The lectin subunit of ricin that binds cell-surface sugars and helps the toxin enter cells. Its sugar-binding activity enables ricin to attach to cells and enter them.
Ricinus communis: A flowering plant native to the Mediterranean Basin, eastern Africa, and India, cultivated for castor oil. This is the plant species whose seeds contain ricin.
Ricin immunotoxin: An engineered molecule combining a cell-targeting antibody or ligand with ricin’s toxic component. Researchers have investigated ricin-derived constructs for selectively killing targeted cells.
Chemical Weapons Convention: An international treaty prohibiting the development, production, stockpiling, and use of chemical weapons. Ricin is subject to the Convention’s restrictions on toxic chemicals used as weapons.
Botulinum toxin: A bacterial neurotoxin that blocks neurotransmitter release at neuromuscular junctions. Unlike ricin, it disrupts nerve signaling rather than directly disabling ribosomes.