Ricin.

Description

Ricin is a heterodimeric ribosomeinhibiting protein consisting of an A-chain (RTA), linked by a disulphide bond to the B-chain (RTB). The total molecular weight is 66 000 Da, with the A-chain contributing 32 kDa, and the B-chain 34 kDa. The A-chain is a globular protein composed of 267 amino acids containing eight alpha helices and eight beta sheets, with the toxin’s substrate binding site located within the cleft. The B-chain is the binding lectin composed of 262 amino acids, shaped like a barbell, and has a binding site specific for membrane sugars at each end (galactose and N-acetyl galactosamine).

Chemical Properties

Various tests for the detection of Ricin are avail- able, including “Pro-Strips” from Avant Technologies, the BIO-911? test strip developed by Osborn Scientific Group, Lakeside AZ. This one-step test is reported to detect, within minutes, the presence of minute quantities of the toxin (less than 50 nanograms); the freeze-dried assay kit to detect crude Ricin called Ruggedized Advanced Pathogen Identification Device (Rapid)?, Rapid LT, and Razor instrument developed by Idaho Technologies, Inc. Ricin is detectable in urine, plasma, and environmental samples. Instant Chek Abrin/Ricin Detection Kit, Catalog Number: IC-RA-003-10 Kit Contents: 10 test units each test contains two tests (one Abrin and one Ricin) per unit, lyophilized reagent, reconstitution buffer, wash buffer, transfer pipettes, instruction booklet. Ey Laboratories, Inc, 107 N. Amphlett Blvd, San Mateo, CA. 94401 USA, Toll Free (North America)1-800-821-0044; Telephone: 1-650- 342-3296, Option 2 or 3 Fax. 11 (650) 342 2648. Also, in 2009, researchers at Yeshiva University’s Albert Einstein College of Medicine have developed an accurate test. Polymerase Chain Reaction (PCR) can detect castor bean DNA in most Ricin preparations. See also “Water Detection,” below.

Uses

As a tool in studies of cell-surface properties; experimentaly in cancer research.

Uses

Ricin is the most well known, and ubiquitous, of the toxalbumins. Castor beans are used in the production of castor oil, a major constituent in lubricants, brake fluids, and hydraulic fluids. During the production process, 5–10% of the aqueous phase, also known as ‘waste mash,’ is recoverable as ricin. In addition, castor beans and jequirity peas are used extensively throughout Mexico and Central America for ornamental purposes in items such as necklaces, prayer or rosary beads, and the rattles in musical shakers (maracas).
Other than ricin, several other toxalbumins exist in nature, including Wisteria frutescens, Abrus precatorius (precatory bean), Abrin, Wisteria sinensis (Chinese wisteria), Viscum album (European mistletoe), Phoradendron tomentosum (Christmas mistletoe), and Trichosanthes kirilowii (Chinese cucumber).

Uses

Ricin is a toxin found in the seeds of the castor oil plant, Ricinnus communis. The plant is cultivated commercially for its oil, but is also widespread as a weed and used as an ornamental plant. Approximately 3–5% of the waste from castor oil production is ricin. The major uses of ricin are as a chemical warfare agent, as a tool in studies of cell surface properties, and experimentally in cancer research. Ricin-A conjugate has been used experimentally in AIDS research. Low concentrations of the powders (0.3%) are marketed as a mole killer.
Its preferred use seems to be as an assassin’s weapon and there are documented cases of umbrellas being used as a means of injecting ricin into human targets. It has also been found at postal facilities and mailings to a US Senator’s office.

Potential Exposure

Potentially Fatal. Ricin, a protein found in castor beans, is one of the most incredibly potent and lethal substances known to humankind2500 μg (an amount capable of fitting on the head of a pin)—is capable of killing an adult within a few days. The castor plant, and their beans, is an important industrial plant and vast amounts of castor plants and beans are grown commer- cially. The castor plant, originally native to Africa, is an attractive plant that can be found in people’s yards as orna- mentals. If the flowers are removed before they produce seeds, the risk of accidents can be averted. Ricin poisoning can occur following accidental ingestion of castor beans. In some countries castor beans are used as beads on neck- laces; both children and adults have eaten just a few beans and died from the poison. This invasive 8 to 10 foot tall plant can be found in more than 25 US states and other places, including Australia. The plants die in freezing weather. The beans are turned into important and valuable industrial products. After the castor oil is squeezed from the castor beans, about 5% of what’s left is Ricin. Although people have used weak castor oil as a laxative, purgative, and general folk-medicine “cure all,” pure Ricin kills in a few days. Ricin gets into the body’s cells and inhibits protein synthesis. Once this essential mechanism is halted, within hours the body’s systems begins to shut down and the body begins to die. Ricin poisoning is not contagious and does not spread from person to person. Because Ricin isn’t a living thing but rather a chemical made by living things, it probably would NOT make as effective a military weapon as viruses or bacteria like the ebola virus or anthrax. Nevertheless, it would make an effective terrorist weapon because it’s easy to make and easy to use. It is estimated that a ton of Ricin would be required to produce a mass casualty biological weapon. With no known antidote ? , vaccine, or other effective ther- apy available for Ricin poisoning, the threat of this agent being released into the environment as an aerosol, or added to the food or water supply, could be catastrophic. Ricin is extremely hazardous when freeze-dried, forming a light,easily-dispersed powder. For this reason, research labora- tory personnel are usually directed to avoid freeze-drying Ricin. ? Note: Various public and private sector organiza- tions are working on the development of antibody therapy that shows promise in neutralizing Ricin in animals. If suc- cessful, this therapy could result in a vaccine for humans and potentially reduce the threat of Ricin being used as a terrorist weapon.

First aid

No antidote exists for Ricin. Make all exposedpeople go to the nearest hospital emergency department.Make all potentially exposed people shower and changeclothes. In case you have gotten Ricin on your skin or yourclothing, immediately shower and change clothes. See adoctor as soon as possible: since it can take only a day anda half for symptoms to appear, all exposed persons shouldget to a doctor that same day. If exposure includes contactwith Ricin, remove it off or out of the body as quickly aspossible. Treatment needs to be provided in a hospital setting. Make the doctors and nurses aware of the potential forexposure so that they can protect themselves; and providethe most appropriate treatments and therapies. If you haveto wait for medical assistance, make the victim comfortable.If Ricin has been ingested, the airway must be secured andstomach pumping (gastric lavage) may be considered.Vigorous gastric lavage is recommended only if it can bedone shortly after ingestion (generally within 1 h). Risk ofaggravating injury to the lining of the gastrointestinal (GI)tract must be considered.To minimize the effects of the poisoning and to keep thepatient stable, Ricin poisoning is treated through supportivetherapy. The types of supportive medical care would dependon several factors, such as the route by which victim(s) werepoisoned (i.e., whether poisoning was by inhalation, ingestion, eye, or skin exposure). Do not induce vomiting. Rinsemouth, flush stomach with activated charcoal* (if the Ricinhas been very recently ingested), wash out the victim’s eyeswith water, especially if the eyes are red and irritated.Supportive care could include intravenous fluid input andsupport of circulation and respiration; giving medications totreat conditions such as seizure and low blood pressure. Fluidinput is critical, as fluid losses of up to 2-1/2 L are probable.If individual is drowsy or unconscious, do not give anythingby mouth. In the event of vomiting, lean patient forward orplace on left side (head-down position, if possible) to maintain open airway and prevent aspiration. Fluid and electrolytebalance should be monitored and restored if abnormal. Earlyand aggressive IV fluid and electrolyte replacement. If thevictim’s lungs fill with fluid, you administer oxygen if hisbreathing is difficult or labored.*Superactivated charcoal may be of little value for largemolecules such as Ricin.[USAMRICD]

Carcinogenicity

No carcinogenic effects of ricin have been reported. The National Library of Medicine’s on-line database HSDB (Hazardous Substances Data Bank) (http://toxnet.nlm.nih.gov) contains a number of references showing the potential for ricin to be used as an anticancer drug. Ricin has strong cytostatic effect against transplanted malignancies in mice.

storage

Color Code—Blue: Health Hazard/Poison (Toxic):Store in a secure, locked poison location. Store in a cool,dry, well-ventilated area and away from food stuffcontainers.

Shipping

UN3172 Toxins, extracted from living sources, liquid, n.o.s., Hazard Class: 6.1; Labels: 6.1-Poisonous materials, Technical Name Required. UN3462 Toxins, extracted from living sources, solid, n.o.s., Hazard Class: 6.1; Labels: 6.1-Poisonous materials, Technical Name Required.

Toxicity evaluation

Ricin contains two basic components necessary for it to enter cells and inhibit protein synthesis. The ligand portions of the B-chain act to bind to galactose moieties of the cell membrane and facilitate endocytosis of the entire ricin molecule into the cell, where it is transported via endosomes to the Golgi apparatus and endoplasmic reticulum. Once there, the A-chain is translocated into the cytosol where N-glycosidase modifies a base (A4324) in an exposed loop of the 28S rRNA fragment of the 60S RNA chain. Requiring no energy or cofactors, it catalytically and irreversibly inactivates the 60S ribosomal subunit, halting all further protein synthesis, and thereby causing severe cytotoxic effects on multiple organ systems.

Incompatibilities

Product is considered stable at ambient temperature. Ricin and other protein toxins can be destroyed by exposure to 0.1% sodium hypochlorite solution (household bleach) for 10 minutes. The toxic portion of Ricin is heat stable at ambient temperatures and begins to decompose at 60℃/140 ℃. At 80℃/176 ℃ most of the toxicity is lost in about 30 minutes. When heated to decomposition, Ricin emits toxic nitrogen oxides. Avoid contact with strong oxidizers.

Waste Disposal

Do not clean-up or dispose of Ricin, except under supervision of a specialist.