Wikipedia:WikiProject Chemicals/Chembox validation/VerifiedDataSandbox and Selenomethionine: Difference between pages

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| verifiedrevid = 464388829

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| IUPACName = 2-Amino-4-(methylselanyl)butanoic acid

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| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}

| CASNo_Ref = {{cascite|correct|CAS}}

| CASNo = 3211-76-5

| CASNo_Comment = (L)

| CASNo1_Ref = {{cascite|correct|CAS}}

| CASNo1 = 1464-42-2

| CASNo1_Comment = (D/L)

| PubChem = 15103

| UNII_Ref = {{fdacite|correct|FDA}}

| UNII_Comment = (L)

| UNII1_Ref = {{fdacite|correct|FDA}}

| UNII1 = J9V40V4PKZ

| UNII1_Comment = (D/L)

|Section2={{Chembox Properties

| Formula = C₅H₁₁NO₂Se

| MolarMass = 196.106 g/mol

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'''Selenomethionine''' (SeMet) is a naturally occurring [[amino acid]]. The <small>L</small>-selenomethionine [[L-enantiomer|enantiomer]] is the main form of [[selenium]] found in [[Brazil nuts]], [[cereal grains]], [[soybeans]], and grassland [[legumes]], while [[Se-methylselenocysteine|''Se''-methylselenocysteine]], or its [[Transglutaminase|γ-glutamyl derivative]], is the major form of selenium found in ''[[Astragalus (plant)|Astragalus]]'', ''[[Allium]]'', and ''[[Brassica]]'' species.<ref>{{cite journal|first=P. D. |last=Whanger |title=Selenocompounds in plants and animals and their biological significance |journal=Journal of the American College of Nutrition |volume=21 |issue=3 |pages=223–32 |date=2002|doi=10.1080/07315724.2002.10719214 |pmid=12074249 |s2cid=20483595 }}</ref> ''In vivo'', selenomethionine is randomly incorporated instead of [[methionine]]. Selenomethionine is readily oxidized.<ref>{{cite journal|first1=E. |last1=Block |first2=M. |last2=Birringer |first3=W. |last3=Jiang |first4=T. |last4=Nakahodo |first5=H. J. |last5=Thompson |first6=P. J. |last6=Toscano |first7=H. |last7=Uzar |first8=X. |last8=Zhang |first9=Z. |last9=Zhu |title=''Allium'' chemistry: synthesis, natural occurrence, biological activity, and chemistry of ''Se''-alk(en)ylselenocysteines and their γ-glutamyl derivatives and oxidation products |journal=Journal of Agricultural and Food Chemistry |volume=49 |date=2001|issue=1 |pages=458–70 |doi=10.1021/jf001097b |pmid=11305255 }}</ref>

Selenomethionine's antioxidant activity arises from its ability to deplete [[reactive oxygen species]]. [[Selenium]] and [[methionine]] also play separate roles in the formation and recycling of [[glutathione]], a key endogenous antioxidant in many organisms, including humans.

== Substitution chemistry issues ==

Selenium and sulfur are [[chalcogen]]s that share many chemical properties so the substitution of methionine with selenomethionine may have only a limited effect on protein structure and function. However, the incorporation of selenomethionine into tissue proteins and keratin in cattle, birds, and fish causes [[Selenium#Toxicity|alkali disease]].<ref>{{Cite journal|last1=O'Toole|first1=D.|last2=Raisbeck|first2=M. F.|date=1995|title=Pathology of experimentally induced chronic selenosis (alkali disease) in yearling cattle|journal=Journal of Veterinary Diagnostic Investigation|volume=7|issue=3|pages=364–373|doi=10.1177/104063879500700312|issn=1040-6387|pmid=7578453|doi-access=free}}</ref><ref>{{Cite journal|last1=Spallholz|first1=Julian E.|last2=Hoffman|first2=David J.|date=2002|title=Selenium toxicity: cause and effects in aquatic birds|journal=Aquatic Toxicology|location=Amsterdam, Netherlands|volume=57|issue=1–2|pages=27–37|issn=0166-445X|pmid=11879936|doi=10.1016/S0166-445X(01)00268-5|s2cid=28251689 |url=https://digitalcommons.unl.edu/cgi/viewcontent.cgi?article=1583&context=usgsstaffpub}}<!--http://digitalcommons.unl.edu/cgi/viewcontent.cgi?article=1583&context=usgsstaffpub--></ref><ref>{{Cite journal|last=Lemly|first=A.Dennis|date=1997|title=A Teratogenic Deformity Index for Evaluating Impacts of Selenium on Fish Populations|journal=Ecotoxicology and Environmental Safety|volume=37|issue=3|pages=259–266|doi=10.1006/eesa.1997.1554|pmid=9378093|issn=0147-6513|url=https://zenodo.org/record/1229572}}</ref>

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.

Incorporation of selenomethionine into proteins in place of [[methionine]] aids the structure elucidation of proteins by [[X-ray crystallography]] using [[single wavelength anomalous dispersion|single-]] or [[multi-wavelength anomalous diffraction]] (SAD or MAD).<ref>{{cite journal|first=W. A. |last=Hendrickson |title=Maturation of MAD phasing for the determination of macromolecular structures |journal=Journal of Synchrotron Radiation |volume=6 |issue=4 |pages=845–851 |date=1999|doi=10.1107/S0909049599007591 |doi-access=free }}</ref> The incorporation of heavy atoms such as selenium helps solve the [[phase problem]] in X-ray crystallography.<ref>{{cite book|first=A. M. |last=Larsson |contribution=Preparation and crystallization of selenomethionine protein |series=IUL Biotechnology Series |volume=8 |title=Protein Crystallization |pages=135–154 |date=2009}}</ref>

== Dietary intake ==

Selenomethionine is readily available as a dietary supplement. It has been suggested by nutritionists that selenomethionine, as an organic form of selenium, is easier for the human body to absorb than [[selenous acid|selenite]], which is an inorganic form.<ref name="CL_CancerPrevention">{{cite web |url= http://www.consumerlab.com/reviews/Supplements_for_Cancer_Prevention_Green_Tea_Lycopene_and_Selenium/cancerprevention/ |title= Product Review: Supplements for Cancer Prevention (Green Tea, Lycopene, and Selenium) |publisher= [[ConsumerLab.com]] |access-date=2008-04-20 |quote= Selenium supplements are available in organic and inorganic forms. Some research suggests that the inorganic form, selenite, is harder for the body to absorb than organic forms such as selenomethionine (selenium bound to methionine, an essential amino acid) or high-selenium yeast (which contains selenomethionine). A recent clinical trial found that selenomethionine had 19% better absorption than selenite; absorption from selenium yeast was about 10% better than selenite.}}</ref> It was determined in a clinical trial that selenomethionine is absorbed 19% better than selenite.<ref name="CL_CancerPrevention"/>

==See also==

* [[Selenocysteine]], another selenium-containing amino acid, but one that is incorporated into specific locations of specific proteins as directed by the genetic code.

* [[Selenoprotein]]

* [[Canadian Reference Materials|Canadian Reference Material]] of selenomethionine

==References==

{{reflist|30em}}

==External links==

* [http://xray.bmc.uu.se/hicup/MSE/ PDB file for MSE] {{Webarchive|url=https://web.archive.org/web/20180920083516/http://xray.bmc.uu.se/hicup/MSE/ |date=2018-09-20 }}

* [http://www.ebi.ac.uk/thornton-srv/databases/cgi-bin/pdbsum/GetPage.pl?pdbcode=n/a&template=het2pdb.html&param1=MSE PDB entries containing Het Group MSE]

[[Category:Alpha-Amino acids]]

[[Category:Organoselenium compounds]]

[[Category:Selenium(−II) compounds]]

[[Category:Selenoethers]]