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Toxalbumin
Toxalbumins are toxic plant proteins that disable ribosomes and thereby inhibit protein synthesis, producing severe cytotoxic effects in multiple organ systems. They are dimers held together by a disulfide bond and comprise a lectin (carbohydrate-binding protein) part which binds to the cell membrane and enables the toxin part to gain access to the cell contents. Toxalbumins are similar in structure to AB toxins found in cholera, tetanus, diphtheria, botulinum and others; and their physiological and toxic properties are similar to those of viperine snake venom. Toxalbumins were first described in about 1890 by Ludwig Brieger (1849–1919) and Sigmund Fraenkel (1868–1939), associates of the organic chemist Eugen Baumann. Brieger first used the term toxin. Toxalbumins notably are present in the plant families Leguminosae and Euphorbiaceae, occurring for instance in ''Robinia pseudoacacia'', ''Abrus precatorius'', ''Jatropha curcas'', '' Croton gratissimus'' and ''Ricinus ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
AB Toxin
The AB toxins are two-component protein complexes secreted by a number of pathogenicity, pathogenic bacteria, though there is a pore-forming AB toxin found the eggs of a snail. They can be classified as Exotoxin#Type III: intracellular, Type III toxins because they interfere with internal cell function. They are named AB toxins due to their components: the "A" component is usually the "active" portion, and the "B" component is usually the "binding" portion. The "A" subunit possesses enzyme activity, and is transferred to the host cell (biology), cell following a conformational change in the membrane-bound transport "B" subunit. These proteins consist of two independent polypeptides, which correspond to the A/B subunit Moiety (chemistry), moieties. The enzyme component (A) enters the cell (biology), cell through endosomes produced by the oligomeric binding/translocation protein (B), and prevents actin polymerisation through ADP-ribosylation of monomeric G-actin. Examples of the "A" ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ricinus Communis
''Ricinus communis'', the castor bean or castor oil plant, is a species of perennial flowering plant in the spurge family, Euphorbiaceae. It is the sole species in the monotypic genus, ''Ricinus'', and subtribe, Ricininae. The evolution of castor and its relation to other species are currently being studied using modern genetic tools. It reproduces with a mixed pollination system which favors selfing by geitonogamy but at the same time can be an out-crosser by anemophily (wind pollination) or entomophily (insect pollination). Its seed is the castor bean, which, despite its name, is not a bean (that is, the seed of many Fabaceae). Castor is indigenous to the southeastern Mediterranean Basin, Eastern Africa, and India, but is widespread throughout tropical regions (and widely grown elsewhere as an ornamental plant). Castor seed is the source of castor oil, which has a wide variety of uses. The seeds contain between 40% and 60% oil that is rich in triglycerides, mainly ricinolei ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lectin
Lectins are carbohydrate-binding proteins that are highly specific for sugar groups that are part of other molecules, so cause agglutination of particular cells or precipitation of glycoconjugates and polysaccharides. Lectins have a role in recognition at the cellular and molecular level and play numerous roles in biological recognition phenomena involving cells, carbohydrates, and proteins. Lectins also mediate attachment and binding of bacteria, viruses, and fungi to their intended targets. Lectins are ubiquitous in nature and are found in many foods. Some foods, such as beans and grains, need to be cooked, fermented or sprouted to reduce lectin content. Some lectins are beneficial, such as CLEC11A, which promotes bone growth, while others may be powerful toxins such as ricin. Lectins may be disabled by specific mono- and oligosaccharides, which bind to ingested lectins from grains, legumes, nightshade plants, and dairy; binding can prevent their attachment to the carbohy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Toxin
A toxin is a naturally occurring organic poison produced by metabolic activities of living cells or organisms. Toxins occur especially as a protein or conjugated protein. The term toxin was first used by organic chemist Ludwig Brieger (1849–1919) and is derived from the word toxic. Toxins can be small molecules, peptides, or proteins that are capable of causing disease on contact with or absorption by body tissues interacting with biological macromolecules such as enzymes or cellular receptors. Toxins vary greatly in their toxicity, ranging from usually minor (such as a bee sting) to potentially fatal even at extremely low doses (such as botulinum toxin). Toxins are largely secondary metabolites, which are organic compounds that are not directly involved in an organism's growth, development, or reproduction, instead often aiding it in matters of defense. Terminology Toxins are often distinguished from other chemical agents strictly based on their biological origin. Le ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Euphorbiaceae
Euphorbiaceae, the spurge family, is a large family of flowering plants. In English, they are also commonly called euphorbias, which is also the name of a genus in the family. Most spurges, such as ''Euphorbia paralias'', are herbs, but some, especially in the tropics, are shrubs or trees, such as ''Hevea brasiliensis''. Some, such as ''Euphorbia canariensis'', are succulent and resemble cacti because of convergent evolution. This family has a cosmopolitan global distribution. The greatest diversity of species is in the tropics, however, the Euphorbiaceae also have many species in nontropical areas of all continents except Antarctica. Description The leaves are alternate, seldom opposite, with stipules. They are mainly simple, but where compound, are always palmate, never pinnate. Stipules may be reduced to hairs, glands, or spines, or in succulent species are sometimes absent. The plants can be monoecious or dioecious. The radially symmetrical flowers are unisexual, w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Robinia Pseudoacacia
''Robinia pseudoacacia'', commonly known in its native territory as black locust, is a medium-sized hardwood deciduous tree, belonging to the tribe Robinieae of the legume family Fabaceae. It is endemic to a few small areas of the United States, but it has been widely planted and naturalized elsewhere in temperate North America, Europe, Southern Africa and Asia and is considered an invasive species in some areas. Another common name is false acacia, a literal translation of the specific name (''pseudo'' reek ''ψευδο-''meaning fake or false and ''acacia'' referring to the genus of plants with the same name). Description Black locust reaches a typical height of with a diameter of . It is a very upright tree with a straight trunk and narrow crown that grows scraggly with age. The dark blue-green compound leaves with a contrasting lighter underside give this tree a beautiful appearance in the wind and contribute to its grace. Black locust is a shade-intolerant species and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Abrus Precatorius
''Abrus precatorius'', commonly known as jequirity bean or rosary pea, is a herbaceous flowering plant in the bean family Fabaceae. It is a slender, perennial climber with long, pinnate-leafleted leaves that twines around trees, shrubs, and hedges. The plant is best known for its seeds, which are used as beads and in percussion instruments, and which are toxic because of the presence of abrin. Ingestion of a single seed, well chewed, can be fatal to both adults and children. The plant is native to Asia and Australia. It has a tendency to become weedy and invasive where it has been introduced. Names ''Abrus precatorius'' is commonly known as jequirity, Crab's eye, or rosary pea, paternoster pea, love pea, precatory pea or bean, prayer bead, John Crow Bead, coral bead, red-bead vine, country licorice, Indian licorice, wild licorice, Jamaica wild licorice, gundumani/kundumani (in India/Tamil), Akar Saga, coondrimany, gidee gidee, Jumbie bead,Mendes (1986), p. 79. ratti / rettee / r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
