N-Acetylmethionine

The N-terminal methionine is posttranslationally acetylated [86], Similar N-term-inal sequences were found in several other proteins that contain N-acetylmethionine as the N-terminal amino acid, suggesting that the signal for acetylation may be the Met-Asp or Met-Glu sequence [71],... 

The rate of formation of sulphoxides from sulphides and iodine in aqueous solution has been found to be relatively slow. It may be, however, accelerated by certain nucleophiles, such as phthalate ion S hydrogen phosphate ion and E(-cyclodextrin phosphate ion . The selective oxidation of JV-acetylmethionine and N-acetylmethionine methyl ester to the corresponding S-oxides was achieved using iodine in the presence of dicarboxylate ions. 

Fig. 27. Stereoview of the crystal structure of 1 1 DTU ethyl N-acetylmethioninate, with eight entities of the complex in the unit-cell461...

Quench the oxidation by the addition to the peptide solution of at least a 4-fold molar excess of N-acetylmethionine or sodium sulfite over the concentration of periodate in the reaction mixture. Pre-dissolve the quencher in buffer at a higher concentration prior to adding an aliquot of it to the reaction solution. React for 10 minutes. 

Quench the reaction by immediate gel filtration on a desalting column. If a dextran-based resin is used for the chromatography, the support itself will react with sodium periodate to quench excess reagent. Alternatively, N-acetylmethionine may be added to quench the reaction, because the thioether of the methionine side chain will react with periodate to form sulfoxide or sulfone products (Geoghegan and Stroh, 1992). In addition, sodium... 

One-electron oxidation mechanism of methionine methyl ester (MME), N-acetylmethionine (NAM), N-acetylmethionine amide (NAMA), and N-acetylmethionine methyl ester (NAMME) employing OH radicals were studied by means of pulse radiolysis in aqueous solutions. 

The effect of N-acetyl substitution in methionine on the nature of transients formed after one-electron oxidation was studied as a function of pH and NAM concentration. The observed absorption bands with X = 290 nm, 360 nm, and 490 nm were respectively assigned to a-(alkylthio)alkyl, hydroxysulfuranyl and dimeric radical cations with intermolecular three-electron bond between sulfur atoms. N-acetylmethionine amide (NAMA) (Chart 7) represents a simple chemical model for the methionine residue incorporated in a peptide. Pulse radiolysis studies coupled to time-resolved UV-Vis spectroscopy and conductivity detection of N-acetyl methionine amide delivered the first experimental evidence that a sulfur radical cation can associate with the oxygen of an amide function vide infra). ... 

In a neutral amide -C(=0)-NH2, the carbonyl oxygen atom represents the better nucleophile compared to nitrogen atom. This fact is corroborated by pulse radiolysis studies of N-acetylmethionine methyl ester (NAMME) (Chart 7) showing similar kinetic and spectral features to NAMA. The theoretical parameters calculated by DPT (including TD-DFT) methods support to a large extent the experimentally identified one-electron oxidation mechanism of NAMA. ... 

The amino acid sequences of many mammalian metallothioneins are known." They all contain 61 residues with the cysteine residues distributed along the full length of the polypeptide chain, and with N-acetylmethionine and alanine at the N- and C-termini, respectively. All 20 cysteine residues are involved in the binding of up to seven metal ions via thiolate linkages. A typical amino acid sequence is shown in Figure 44. 

Figure 8.8 Complex forms of CRM 6 with (a) (R)- and (S)-N-acetylmethionine methylester and (b) (R)- and (5)-N-3,5-dinitrobenzoylleucine methylester. White, light-gray, dark-gray, and black balls, represent hydrogen, carbon, nitrogen, and ojg gen, respectively.

Acetyl-isopropyl benzol. Seep-Isopropylacetophenone Acetylmetacresol. See m-Cresyl acetate Acetyl methionine (INCI) N-Acetylmethionine. See N-Acetyl-L-methionine N-Acetyl-L-methionine... 

Synonyms N-Acetyl-L-2-amino-4-(methylthio) butyric acid Acetyl methionine (INCI) N-Acetylmethionine Methionamine L-Methionine, N-acetyl-... 

Synonyms Elastin, compd. with methylsilanol, N-acetylmethionine ester Elastin, reaction prods, with N-acetyl-L-methionine and methylsilanetriol... 

Definition Ester of N-acetylmethionine and methylsilanol elastinate Uses Antistat, skin conditioner, hair conditioner in cosmetics Trade Name Synonyms Methiosilane C [Exsymol http //www.exsymoi.com]... 

Definition Gold salt of N-acetylmethionine Uses Detoxification, transpeptidization element, and keratin, enzyme, and hormone formation promoters, dermal moisturizers for cosmetics... 

Definition Manganese salt of N-acetylmethionine Uses Skin conditioner in cosmetics detoxification, transpeptidization element, keratin/enzyme/hormone formation promoter, dermal moisturizer for cosmetics Trade Name Synonyms Exsymanganese t[Exsymol http //www.exsymol.com], Exsymol Manganese Acetylmethionate [Exsymol http //www.exsymoi.com-, Biosil Tech. http //www. biosiltech. com] 01 igoelement Manganese [Exsymol http //WWW. exsymol. com]... 

CH3SCH2CH2CHNHCOCH3 radical formed via 6H radical induced decarboxylation of N-acetylmethionine. °) 37% e -transfer. 

L1A1H4 added slowly to DL-N-acetylmethionine in abs. tetrahydrofuran, and refluxed 4 hrs. DL-N-ethylmethioninol. Y 85%.—No elimination of the methylthio group takes place with either LiAlH4 or LiBH4. M. Pohm, M. 91, 363 (1960). 

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