Abrin
From Proteopedia
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Abrin is referred to as a type-2 ribosome-inactivating protein (RIP). The protein contains two chains:<scene name='77/778334/A_chain/1'> α</scene> and <scene name='77/778334/Abrin_b_chain/1'>β</scene> which are connected by a disulfide bond. Both of the chains are <scene name='77/778334/Water/1'>water soluble</scene>. The water molecules hydrolyze the N-C glycosidic bond. The β chain allows the α chain to enter a cell because it attaches to the carbohydrate receptors. The β is composed of the following amino acids: Ile-Val-Glu-Lys-Ser-Lys-Ile-Ser-Ser-Ser-Arg-Tyr-Glu-Pro-Thr. The α chain is known as an N-glycosidase <ref name="Yu">DOI:10.1093/abbs/gmw023</ref>. Once the α chain is in a cell, the chain removes adenine bases and links to the 28S rRNA<ref name="Wooten">DOI: 10.1007/s13181-013-0377-9</ref>. The attachment causes the ribosome to be incompetent when trying to connect to an elongation factor leading to an inhibition of protein synthesis. | Abrin is referred to as a type-2 ribosome-inactivating protein (RIP). The protein contains two chains:<scene name='77/778334/A_chain/1'> α</scene> and <scene name='77/778334/Abrin_b_chain/1'>β</scene> which are connected by a disulfide bond. Both of the chains are <scene name='77/778334/Water/1'>water soluble</scene>. The water molecules hydrolyze the N-C glycosidic bond. The β chain allows the α chain to enter a cell because it attaches to the carbohydrate receptors. The β is composed of the following amino acids: Ile-Val-Glu-Lys-Ser-Lys-Ile-Ser-Ser-Ser-Arg-Tyr-Glu-Pro-Thr. The α chain is known as an N-glycosidase <ref name="Yu">DOI:10.1093/abbs/gmw023</ref>. Once the α chain is in a cell, the chain removes adenine bases and links to the 28S rRNA<ref name="Wooten">DOI: 10.1007/s13181-013-0377-9</ref>. The attachment causes the ribosome to be incompetent when trying to connect to an elongation factor leading to an inhibition of protein synthesis. | ||
== Medical Potential == | == Medical Potential == | ||
| - | Abrin has remained a key interest in a treatment for cancer. In one study, scientists wanted to see if abrin would decrease the number of colon cancer cells in vitro and vivo models. One experiment showed that purified abrin can influence cell cycle arrest and apoptosis. The study states abrin “significantly increased p21 mRNA expression and decreased PCNA, cyclin B1, Ki67 mRNA expression <ref name = "Yu"> which induced a halt in cell growth. For example, p21 can inhibit the CDK2 which regulates the checkpoints of the cell cycle; meaning, if there is an increased level of p21, more CDK2s will be affected. It also stated that abrin can enhance Bcl-2 which causes cytochrome c to be released. With this data, the study suggested that abrin could act as an anticancer treatment for colon cancer; however, a further experiment would have to test abrin’s impact on other cells such as erythrocytes, neurons, or dendritic cells <ref name="Wooten">. | + | Abrin has remained a key interest in a treatment for cancer. In one study, scientists wanted to see if abrin would decrease the number of colon cancer cells in vitro and vivo models. One experiment showed that purified abrin can influence cell cycle arrest and apoptosis. The study states abrin “significantly increased p21 mRNA expression and decreased PCNA, cyclin B1, Ki67 mRNA expression" <ref name = "Yu"> which induced a halt in cell growth. For example, p21 can inhibit the CDK2 which regulates the checkpoints of the cell cycle; meaning, if there is an increased level of p21, more CDK2s will be affected. It also stated that abrin can enhance Bcl-2 which causes cytochrome c to be released. With this data, the study suggested that abrin could act as an anticancer treatment for colon cancer; however, a further experiment would have to test abrin’s impact on other cells such as erythrocytes, neurons, or dendritic cells <ref name = "Wooten">. |
== Negative Effects/Treatment == | == Negative Effects/Treatment == | ||
If an entire rosary pea is ingested, the person will have mild to no symptoms. However, if the shell breaks, the effects of abrin will be released. Abrin is able to induce apoptosis and cell cycle arrest, ingestion of the protein abrin is lethal. If abrin is consumed or inhaled into the human system, symptoms will include difficulty breathing, vomiting, diarrhea, fever, and organ failure. The lethal dose of abrin is 0.1-1 micrograms <ref> doi:10.12659/AJCR.892917</ref> Someone who has been poisoned by abrin will need fluids, a ventilator, and activated charcoal. Another method for suppressing the symptoms of abrin poisoning is to use CRRT and hemoperfusion. CRRT purifies the blood for a day’s duration. CRRT can destroy toxins up to 1-20kDa in size. Hemoperfusion, which is more effective than CRRT can filter the blood and cause a decrease in levels of the toxin. While these methods have the potential for successfully clearing a toxin, it is still essential for those that have been exposed to a toxin to seek medical help, fast and efficiently<ref>doi:10.1097/MD.0000000000007423</ref>. | If an entire rosary pea is ingested, the person will have mild to no symptoms. However, if the shell breaks, the effects of abrin will be released. Abrin is able to induce apoptosis and cell cycle arrest, ingestion of the protein abrin is lethal. If abrin is consumed or inhaled into the human system, symptoms will include difficulty breathing, vomiting, diarrhea, fever, and organ failure. The lethal dose of abrin is 0.1-1 micrograms <ref> doi:10.12659/AJCR.892917</ref> Someone who has been poisoned by abrin will need fluids, a ventilator, and activated charcoal. Another method for suppressing the symptoms of abrin poisoning is to use CRRT and hemoperfusion. CRRT purifies the blood for a day’s duration. CRRT can destroy toxins up to 1-20kDa in size. Hemoperfusion, which is more effective than CRRT can filter the blood and cause a decrease in levels of the toxin. While these methods have the potential for successfully clearing a toxin, it is still essential for those that have been exposed to a toxin to seek medical help, fast and efficiently<ref>doi:10.1097/MD.0000000000007423</ref>. | ||
Revision as of 19:01, 7 January 2019
Abrin
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3D structures of abrin
Updated on 07-January-2019
1abr, 5z37 – IlAbr-A – Indian licorice
5z3i – IlAbr-A + adenine
5z3j – IlAbr-A + nicotinamide
References
- ↑ 1.0 1.1 Yu Y, Yang R, Zhao X, Qin D, Liu Z, Liu F, Song X, Li L, Feng R, Gao N. Abrin P2 suppresses proliferation and induces apoptosis of colon cancer cells via mitochondrial membrane depolarization and caspase activation. Acta Biochim Biophys Sin (Shanghai). 2016 May;48(5):420-9. doi:, 10.1093/abbs/gmw023. Epub 2016 Apr 6. PMID:27055473 doi:http://dx.doi.org/10.1093/abbs/gmw023
- ↑ Wooten JV, Pittman CT, Blake TA, Thomas JD, Devlin JJ, Higgerson RA, Johnson RC. A case of abrin toxin poisoning, confirmed via quantitation of L-abrine (N-methyl-L-tryptophan) biomarker. J Med Toxicol. 2014 Dec;10(4):392-4. doi: 10.1007/s13181-013-0377-9. PMID:24522983 doi:http://dx.doi.org/10.1007/s13181-013-0377-9
- ↑ Huang J, Zhang W, Li X, Feng S, Ye G, Wei H, Gong X. Acute abrin poisoning treated with continuous renal replacement therapy and hemoperfusion successfully: A case report. Medicine (Baltimore). 2017 Jul;96(27):e7423. doi: 10.1097/MD.0000000000007423. PMID:28682903 doi:http://dx.doi.org/10.1097/MD.0000000000007423
- ↑ "Facts About Abrin.” Centers for Disease Control and Prevention, Centers for Disease Control and Prevention, 18 Nov. 2015, emergency.cdc.gov/agent/abrin/basics/facts.asp.
- ↑ Wang J, Gao S, Xin W, Kang L, Xu N, Zhang T, Liu W, Wang J. A novel recombinant vaccine protecting mice against abrin intoxication. Hum Vaccin Immunother. 2015;11(6):1361-7. doi: 10.1080/21645515.2015.1008879. PMID:26086588 doi:http://dx.doi.org/10.1080/21645515.2015.1008879
