Selenomethionine

• L-2- amino-4- ( methylselenyl ) butyric
• D-2 -amino- 4-( methylselenyl ) butyric
• L -selenomethionine
• ( S)- selenomethionine
• D -selenomethionine
• (R ) -selenomethionine

• 3211-76-5 { L -selenomethionine [ Synonyms: ( S)- selenomethionine ]}
• 13091-98-0 {D -selenomethionine [ Synonym: (R ) -selenomethionine ]}

Fixed

265-267 ° C

L -selenomethionine

Risk

R-enantiomer

Template: Infobox chemical / molecular formula search available

L- Selenomethionine [ Synonym: (S) -selenomethionine ] is an α - amino acid, and an analogue of the amino acid L- methionine. Since L -selenomethionine may be fitted in place of L -methionine in proteins, L -selenomethionine is a proteinogenic amino acid.

D -selenomethionine [ Synonym: (R ) -selenomethionine ] is the enantiomer of L -selenomethionine and does not occur in nature. If in this article or in the scientific literature, the configuration is not specified, is " selenomethionine " always for L -selenomethionine.

Properties

Selenomethionine is present predominantly as the "inner salt " or zwitterion, whose formation can be explained by the fact that the proton of the carboxyl group migrates to the lone electron pair of the nitrogen atom of the amino group:

In an electric field, the zwitterion migrates not because it is not loaded as a whole. Strictly speaking, this is at the isoelectric point ( at a certain pH value) of the case, wherein the selenomethionine also has its lowest solubility in water. Selenomethionine is not one of the essential amino acids.

Synthesis

For the synthesis of racemic selenomethionine starts from α -bromo- γ -butyrolactone. Substituting the halo by an amino group by reaction with ammonia. The resulting bromide was neutralized with barium hydroxide. Upon acidification with sulfuric acid, the hydrobromide of produced α -amino- γ -butyrolactone. Its ring opening with potassium acetate and ethanol provides a diketopiperazine, which is also a diol having two primary hydroxyl groups. The nucleophilic substitution with potassium methyl selenide and subsequent acidic work then provides ( RS)- selenomethionine.

Use

L -selenomethionine is used in X-ray structural analysis of proteins. Here is incorporated during recombinant protein synthesis selenomethionine instead of methionine in the proteins. This is the solution of the phase problem ( Patterson method )

L -selenomethionine is also used to supply the people with the trace element selenium: to this amino acid is fed to yeast, the yeast in turn are processed into pharmaceutical preparations continue.

Others

• Abbreviation: SeMet, Sem
• Residual Name: Selenomethionyl -
• Side chain: lipophilic