Selenometionina

Selenometionina
Selenomethionine: chemical structure
Nama
	Nama IUPAC asam 2-Amino-4-(metilselanil)butanoat
	Nama lain MSE
Penanda
Nomor CAS	3211-76-5 (L) ; 1464-42-2 (D/L) ;
Model 3D (JSmol)	Gambar interaktif;
3DMet	{{{3DMet}}}
ChEBI	CHEBI:27585 ;
ChemSpider	14375 ;
Nomor EC
PubChem CID	15103;
Nomor RTECS	{{{value}}}
UNII	964MRK2PEL (L) ; J9V40V4PKZ (D/L) ;
CompTox Dashboard (EPA)	DTXSID7040609 ;
	InChI InChI=1S/C5H11NO2Se/c1-9-3-2-4(6)5(7)8/h4H,2-3,6H2,1H3,(H,7,8) Key: RJFAYQIBOAGBLC-UHFFFAOYSA-N ;
	SMILES C[Se]CCC(C(=O)O)N;
Sifat
Rumus kimia	C5H11NO2Se
Massa molar	196,106 g/mol
	Kecuali dinyatakan lain, data di atas berlaku pada suhu dan tekanan standar (25 °C [77 °F], 100 kPa).
	verifikasi (apa ini ?)
	Referensi

Selenometionina (SeMet) adalah asam amino yang terjadi secara alami. Enantiomer L-selenometionina adalah bentuk utama selenium yang ditemukan dalam kacang Brasil, biji-bijian serealia, kedelai, dan kacang-kacangan lahan rumput, sementara Se-metilselenosisteina, atau turunan γ-glutamilnya, adalah bentuk utama selenium yang ditemukan dalam spesies Astragalus, Allium, dan Brassica.^[1] Secara in vivo, selenometionina dimasukkan secara acak alih-alih metionina. Selenometionina mudah teroksidasi.^[2]

Aktivitas antioksidan selenometionina muncul dari kemampuannya untuk menguras spesi oksigen reaktif. Selenium dan metionina juga memainkan peran terpisah dalam pembentukan dan daur ulang glutation, antioksidan endogen utama dalam banyak organisme, termasuk manusia.

Masalah kimia substitusi

Selenium dan belerang adalah kalkogen yang memiliki banyak sifat kimia yang sama, sehingga substitusi metionina dengan selenometionina mungkin hanya memiliki efek terbatas pada struktur dan fungsi protein. Namun, penggabungan selenometionina ke dalam protein jaringan dan keratin pada sapi, burung, dan ikan menyebabkan penyakit alkali.^[3]^[4]^[5]

Penyakit alkali ditandai dengan kekurusan, kerontokan rambut, deformasi dan kerontokan kuku, hilangnya vitalitas, dan erosi sendi tulang panjang.

Penggabungan selenometionina ke dalam protein sebagai pengganti metionina membantu elusidasi struktur protein dengan kristalografi sinar-X menggunakan difraksi anomali panjang gelombang tunggal atau jamak (SAD atau MAD).^[6] Penggabungan atom berat seperti selenium membantu memecahkan masalah fase dalam kristalografi sinar-X.^[7]

Asupan makanan

Selenometionina tersedia secara luas sebagai suplemen makanan. Ahli gizi telah menyarankan bahwa selenometionina, sebagai bentuk organik selenium, lebih mudah diserap tubuh manusia daripada selenit, yang merupakan bentuk anorganik. Dalam uji klinis ditentukan bahwa selenometionina diserap 19% lebih baik daripada selenit.^[8]

Referensi

^ Whanger, P. D. (2002). "Selenocompounds in plants and animals and their biological significance". Journal of the American College of Nutrition. 21 (3): 223–32. doi:10.1080/07315724.2002.10719214. PMID 12074249. S2CID 20483595.
^ Block, E.; Birringer, M.; Jiang, W.; Nakahodo, T.; Thompson, H. J.; Toscano, P. J.; Uzar, H.; Zhang, X.; Zhu, Z. (2001). "Allium chemistry: synthesis, natural occurrence, biological activity, and chemistry of Se-alk(en)ylselenocysteines and their γ-glutamyl derivatives and oxidation products". Journal of Agricultural and Food Chemistry. 49 (1): 458–70. doi:10.1021/jf001097b. PMID 11305255.
^ O'Toole, D.; Raisbeck, M. F. (1995). "Pathology of experimentally induced chronic selenosis (alkali disease) in yearling cattle". Journal of Veterinary Diagnostic Investigation. 7 (3): 364–373. doi:10.1177/104063879500700312. ISSN 1040-6387. PMID 7578453.
^ Spallholz, Julian E.; Hoffman, David J. (2002). "Selenium toxicity: cause and effects in aquatic birds". Aquatic Toxicology. 57 (1–2). Amsterdam, Netherlands: 27–37. doi:10.1016/S0166-445X(01)00268-5. ISSN 0166-445X. PMID 11879936. S2CID 28251689.
^ Lemly, A.Dennis (1997). "A Teratogenic Deformity Index for Evaluating Impacts of Selenium on Fish Populations". Ecotoxicology and Environmental Safety. 37 (3): 259–266. doi:10.1006/eesa.1997.1554. ISSN 0147-6513. PMID 9378093.
^ Hendrickson, W. A. (1999). "Maturation of MAD phasing for the determination of macromolecular structures". Journal of Synchrotron Radiation. 6 (4): 845–851. doi:10.1107/S0909049599007591.
^ Larsson, A. M. (2009). "Preparation and crystallization of selenomethionine protein". Protein Crystallization. IUL Biotechnology Series. Vol. 8. hlm. 135–154.
^ "Product Review: Supplements for Cancer Prevention (Green Tea, Lycopene, and Selenium)". ConsumerLab.com. Diakses tanggal 2008-04-20. 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.

Pranala luar

PDB file for MSE Diarsipkan 2018-09-20 di Wayback Machine.
PDB entries containing Het Group MSE

[1] Whanger, P. D. (2002). "Selenocompounds in plants and animals and their biological significance". Journal of the American College of Nutrition. 21 (3): 223–32. doi:10.1080/07315724.2002.10719214. PMID 12074249. S2CID 20483595.

[2] Block, E.; Birringer, M.; Jiang, W.; Nakahodo, T.; Thompson, H. J.; Toscano, P. J.; Uzar, H.; Zhang, X.; Zhu, Z. (2001). "Allium chemistry: synthesis, natural occurrence, biological activity, and chemistry of Se-alk(en)ylselenocysteines and their γ-glutamyl derivatives and oxidation products". Journal of Agricultural and Food Chemistry. 49 (1): 458–70. doi:10.1021/jf001097b. PMID 11305255.

[3] O'Toole, D.; Raisbeck, M. F. (1995). "Pathology of experimentally induced chronic selenosis (alkali disease) in yearling cattle". Journal of Veterinary Diagnostic Investigation. 7 (3): 364–373. doi:10.1177/104063879500700312. ISSN 1040-6387. PMID 7578453.

[4] Spallholz, Julian E.; Hoffman, David J. (2002). "Selenium toxicity: cause and effects in aquatic birds". Aquatic Toxicology. 57 (1–2). Amsterdam, Netherlands: 27–37. doi:10.1016/S0166-445X(01)00268-5. ISSN 0166-445X. PMID 11879936. S2CID 28251689.

[5] Lemly, A.Dennis (1997). "A Teratogenic Deformity Index for Evaluating Impacts of Selenium on Fish Populations". Ecotoxicology and Environmental Safety. 37 (3): 259–266. doi:10.1006/eesa.1997.1554. ISSN 0147-6513. PMID 9378093.

[6] Hendrickson, W. A. (1999). "Maturation of MAD phasing for the determination of macromolecular structures". Journal of Synchrotron Radiation. 6 (4): 845–851. doi:10.1107/S0909049599007591.

[7] Larsson, A. M. (2009). "Preparation and crystallization of selenomethionine protein". Protein Crystallization. IUL Biotechnology Series. Vol. 8. hlm. 135–154.

[CL_CancerPrevention-8] "Product Review: Supplements for Cancer Prevention (Green Tea, Lycopene, and Selenium)". ConsumerLab.com. Diakses tanggal 2008-04-20. 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.

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