Gene Association: PCDH17

Se-Methylselenocysteine

C4H9NO2Se (182.9798)

Se-Methylselenocysteine (SeMSC) is a naturally occurring seleno-amino acid that is synthesized by plants such as garlic, astragalus, onions, and broccoli. It cannot be synthesized by higher animals. Unlike selenomethionine, which is incorporated into proteins in place of methionine, SeMSC is not incorporated into any proteins, thereby being fully available for the synthesis of selenium-containing enzymes such as glutathione peroxidase. Selenomethionine is the major seleno-compound in cereal grains (wheat grain, maize, and rice), soybeans, and enriched yeast. Seleno-compounds present in plants may have a profound effect upon the health of animals and human subjects. It is now known that the total Se content cannot be used as an indication of its efficacy, but knowledge of individual selenocompounds is necessary to fully assess the significance. Thus, speciation of the seleno-compounds has moved to the forefront. Since animals and man are dependent upon plants for their nutritional requirements, this makes the types of seleno-compounds in plants even more critical. Se enters the food chain through incorporation into plant proteins, mostly as selenocysteine and selenomethionine at normal Se levels. There are two possible pathways for the catabolism of selenomethionine: (1) a transsulfuration pathway via selenocystathionine to produce selenocysteine, which in turn is degraded to H2Se by the enzyme beta-lyase and (2) a transamination-decarboxylation pathway. It was estimated that 90\\\\% of methionine is metabolized through this pathway and thus could be also the major route for selenomethionine catabolism (PMID: 14748935 , Br J Nutr. 2004 Jan;91(1):11-28.). Selenomethionine is an amino acid containing selenium. The L-isomer of selenomethionine, known as Se-met and Sem, is a common natural food source of selenium. In vivo, selenomethionine is randomly incorporated instead of methionine and is readily oxidized. Its antioxidant activity arises from its ability to deplete reactive species. Selenium and sulfur are chalcogen elements that share many chemical properties and the substitution of methionine to selenomethionine may have no effect on protein structure and function. However, the incorporation of selenomethionine into tissue proteins and keratin in horses causes alkali disease. Alkali disease is characterized by emaciation, loss of hair, deformation and shedding of hooves, loss of vitality, and erosion of the joints of long bones. Se-methyl-L-selenocysteine is an L-alpha-amino acid compound having methylselanylmethyl as the side-chain. It has a role as an antineoplastic agent. It is a Se-methylselenocysteine, a non-proteinogenic L-alpha-amino acid and a L-selenocysteine derivative. It is a conjugate base of a Se-methyl-L-selenocysteinium. It is a conjugate acid of a Se-methyl-L-selenocysteinate. It is an enantiomer of a Se-methyl-D-selenocysteine. It is a tautomer of a Se-methyl-L-selenocysteine zwitterion. Methylselenocysteine has been used in trials studying the prevention of Prostate Carcinoma and No Evidence of Disease. Se-Methylselenocysteine is a metabolite found in or produced by Escherichia coli (strain K12, MG1655). Methylselenocysteine is a naturally occurring organoselenium compound found in many plants, including garlic, onions, and broccoli, with potential antioxidant and chemopreventive activities. Se-Methyl-seleno-L-cysteine (MSC) is an amino acid analogue of cysteine in which a methylselenium moiety replaces the sulphur atom of cysteine. This agent acts as an antioxidant when incorporated into glutathione peroxidase and has been shown to exhibit potent chemopreventive activity in animal models. Se-Methylselenocysteine (SeMSC) is a naturally occurring seleno-amino acid that is synthesized by plants such as garlic, astragalus, onions and broccoli. Unlike selenomethionine, which is incorporated into proteins in place of methionine, SeMSC is not incorporated into any proteins, thereby being fully available for the synthesis of selenium-containing enzymes such as glutathione peroxidase. 3-(Methylseleno)alanine is found in many foods, some of which are common cabbage, white cabbage, lima bean, and cauliflower. D020011 - Protective Agents > D016588 - Anticarcinogenic Agents C26170 - Protective Agent > C275 - Antioxidant D000970 - Antineoplastic Agents Se-Methylselenocysteine, a precursor of Methylselenol, has potent cancer chemopreventive activity and anti-oxidant activity. Se-Methylselenocysteine is orally bioavailable, and induces apoptosis[1][2]. Se-Methylselenocysteine, a precursor of Methylselenol, has potent cancer chemopreventive activity and anti-oxidant activity. Se-Methylselenocysteine is orally bioavailable, and induces apoptosis[1][2].