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Methionine, sulfoxide 2-amino-4-

The place of L-glutamine in hyaluronate synthesis is shown by experiments with methionine sulfoxide. Since methionine sulfoxide (2-amino-4-methylsulfinylbutyric acid) inhibits L-glutamine formation the addition of the sulfoxide to a culture of hemolytic streptococci inhibits hexosamine synthesis and, consequently, hyaluronate formation. This inhibition can take place at concentrations of methionine sulfoxide which are low enough not to inhibit hyaluronate synthesis with L-glutamine. ... [Pg.317]

Sulfoxides occur widely in small concentrations in plant and animal tissues, eg, aHyl vinyl sulfoxide [81898-53-5] in garlic oil and 2,2 -sulfinylbisethanol [3085-45-8] as fatty esters in the adrenal cortex (1,2). Homologous methyl sulfinyl alkyl isothiocyanates, which are represented by the formula CH3SO(CH2) NCS, where n = 3 [37791-20-1], 4 [4478-93-7], 5 [646-23-1], 8 [75272-81-0], 9 [39036-83-4], or 10 [39036-84-5], have been isolated from a number of mustard oils in which they occur as glucosides (3). Two methylsulfinyl amino acids have also been reported methionine sulfoxide [454-41-1] from cockroaches and the sulfoxide of i -methylcysteine, 3-(methylsulfinyl)alaiiine [4740-94-7]. The latter is the dominant sulfur-containing amino acid in turnips and may account in part for their characteristic odor (4). [Pg.107]

The oxidation of cysteine, as well as other amino acids, was studied by Mudd et a/. Individual amino acids in aqueous solution were exposed to ozone the reported order of susceptibility was cysteine, methionine, tryptophan, tyrosine, histidine, cystine, and phenylalanine. Other amino acids were not affected. This order is similar to that for the relative susceptibility of amino acrids to radiation and to lipid peroxides. Evaluation of the ozonization products revealed that cysteine was converted to cysteic acid, as well as cystine methionine to methionine sulfoxide tryptophan to a variety of pioducrts, including kynurenine and N-formylkynurenine tyrosine also to a variety of products, includiitg dihydroxyphenylalanine histidine to ammonia, proline, and other compounds and cystine in part to cysteic acid. In some cases, the rate and end products depended on the pH of the solution. [Pg.350]

These techniques have been used successfully in the micro-Zdman degradation of the enzyme mouse sarcoma dihydrofolate reductase to obtain the amino acid sequence of the first 25 amino acids 455). Similarly, RPC has been used in coqjunction with the automated Edman technique for sequencing 32 residues of myoglobin 456). Methionine and its oxidation products, methionine sulfoxide and methionine sulfone, in methionine fortified foods have been analyzed as their dansyl derivatives 457). Lysine has been determined as its dansyl derivative in a study in which the stability of lysine in fortified wheat flour was evaluated (458). [Pg.317]

The analysis of methionine and cysteine is problematic. The sulfur containing side chains of these amino acids are prone to oxidation. The standard hydrochloric acid hydrolysis will cause the partial conversion of these amino acids into cystine, cysteine, cysteine sulfinic acid, cysteic acid, methionine, methionine sulfoxide, and methionine sulfone. The classic strategy (79) for dealing with this problem is simply to drive the oxidative process to completion (i.e., convert all the cyst(e)ine to cysteic acid) and then to analyze chromatographically for cysteic acid and/or methionine sulfone. This is traditionally accomplished by a prehydrolysis treatment of the sample with performic acid. While this method has sufficed over the years, the typical recovery (85 -90%) and precision (4% intra- and 15% interlaboratory) have been poor (80). [Pg.68]

Actually the irradiation chemistry of even simple amino acids and peptides is much more complex than these equations imply, and many other radiochemical products have been reported (13, 14, 49). These include glyoxylic acid, formaldehyde, hydrogen peroxide, carbon dioxide, succinic acid, aspartic acid, diaminosuccinic acid, methylamine, methane, dimethyl mercaptan, a-aminobutyric acid, methionine sulfoxide, methinonine sul-fone, methionine sulfoxime, homocysteic acid, and several unidentified nitrogen compounds (46, 51). [Pg.44]

In addition to cytochrome P-450 induction, other diet induced metabolic effects are likely to be involved in carcinogenesis. High temperature processing or long-term storage of foods with attendant exposure to oxygen can lead to the formation of lipid peroxides and oxidized sulfur amino acids in the food. The partially oxidized S-amino acids cystine monoxide (CMO) and methionine sulfoxide (MSO) are nutritionally available, but require in vivo conversion to the reduced amino acids at the... [Pg.156]

Male Sprague Dawley rats, seven days post weanling (Bantin and Kingman, Inc., Fremont, CA) were fed pelleted rodent chow (5001, Ralston Purina Co., St. Louis, MO) or modified AIN-76 diets (BioServ, Inc., Frenchtown, NJ) with or without added sulfur amino acids. Chow, diets, and water were supplied to the rats ad libitum. The AIN-76 diet (16) was modified to contain 12% casein (normally 20% casein), and the weight difference made up with cornstarch. The normal methionine supplement was not included. The cornstarch and sucrose portions were held separately from the casein/vitamin/mineral (CVM) mixture for the purpose of mixing amino acids with the cornstarch and sucrose (CsS). Methionine (MET), methionine sulfoxide (MSO) and cysteine sulfinic acid (CSA) were obtained from Sigma Chemical Co., St. Louis, MO. Cysteine monoxide (CMO) was prepared by the method of Savige et al., (17). [Pg.157]

It was confirmed later that free cysteic acid and free methionine sulfone were not biologically available (63, 64,138) and that free methionine sulfoxide was partly available. Miller and Samuel (64) observed that the food efficiency of a mixture of free amino acids was lower when the methionine source was replaced by methionine sulfoxide. The food efficiency was restored when 50% of the methionine sulfoxide was replaced by free methionine. Gjoen and Njaa (66) confirmed that free methionine sulfoxide was nearly as available as methionine when the amino acid mixture contained cystine. This suggests that methionine sulfoxide is reduced before it is used for protein synthesis. In order to elucidate this point, we have compared the metabolic transit of free methionine sulfoxide with that of free methionine. [Pg.105]

The reactive site of i-PI has a Ala-Ile-Pro-Met Ser-Ile-Pro-Pro sequence where the asterisk indicates the bond cleaved when i-PI pro-tase complexes are dissociated at high pH or by using nucleophiles. We have synthesized a number of peptides with the amino acid sequence at the ai-PI reactive site and have shown them to be perfectly adequate substrates for human leukocyte elastase. However, oxidation of the methionine residue of the substrates to a methionine sulfoxide residue (see Table III) almost completely destroys their reactivity toward human leukocyte elastase and other proteases (8,9). Oxidation of ai-PI itself destroys its ability to inhibit most proteases (10). [Pg.345]

Methionine Sulfoxide and Other Combined Amino Acids in the German Cockroach... [Pg.108]

Alkaline hydrolysis of cockroach residues subsequent to extraction under nitrogen with 80% ethanol yielded methionine and methionine sulfoxide in a ratio of 10 to 1. Additional evidence for the presence of combined methionine sulfoxide was obtained by measuring the amount of methionine sulfoxide-S35 in acid and enzymatic hydrolyzates after assimilation of Na2S3504. The data are believed to be indicative of naturally occurring peptide- or polysaccharide -bound methionine sulfoxide. Other combined amino acids were determined by ion exchange chromatography of the 5% trichloroacetic acid-insoluble cockroach residues after hydrolysis with acid or alkali. /3-Alanine, normally present only in the soluble fraction of an organism, was found in the insoluble, proteinaceous residue. [Pg.108]

Reports of the presence of methionine sulfoxide are less frequent with respect to protein hydrolyzates than to free amino acid extracts. This is at least partially due to the fact that reduction and other changes occur upon hydrolysis with hydrochloric acid (16). The extent of decomposition depends on the conditions of hydrolysis and may approach 100%. One occasionally finds a published report of an amino acid analysis of protein in which data for methionine sulfoxide but not methio-... [Pg.108]

Only a small number of proteins and peptides have been analyzed by various investigators by methods designed specifically to determine whether methionine sulfoxide is one of the constituent amino acids. One of these, an analog of the a-melanocyte-stimulating hormone from bovine pituitary glands (9), was found to contain the sulfoxide. However, the authors expressed some concern over the possibility of oxidation during isolation of the sample. [Pg.109]

The present investigation was undertaken to determine if the methionine sulfoxide found by several investigators in insect tissue is a normal constituent of the amino acid pool and of protein. The amino acid composition of cockroach protein was simultaneously determined both qualitatively and quantitatively, since such data are available for few species of insects. [Pg.109]

In order to maintain uniform conditions, all hydrolyzates or extracts were chromatographed simultaneously in the same chamber. A chromatogram of a standard amino acid mixture was used to locate the positions of methionine, methionine sulfoxide, and a second methionine sulfoxide spot formed as a result of oxidation of methionine during drying of the solvent used in the first direction. [Pg.112]

Radioactivity was measured on the chromatograms with an end-window counting tube (4) following visualization of the amino acids with ninhydrin. The extracts and hydrolyzates from the methionine sulfoxide adsorption test were diluted to 100 ml. with water and 1-ml. aliquots were transferred to sample pans and dried for the estimation of radioactivity. [Pg.112]

Some amino acids may be oxidized by reacting with free radicals formed by lipid oxidation. Methionine can react with a lipid peroxide to yield methionine sulfoxide. Cysteine can be decomposed by a lipid free radical according to the following scheme ... [Pg.99]

There has been no report on the spectrum of methionine sulfone, which is found in hydrolyzates of performate-oxidized proteins. It will probably be not very different from cysteic acid at wavelengths > 2000 A, since simple sulfones are generally transparent to 1800 A (Koch, 1950). Methionine sulfoxide is a stable amino acid found in human urine, in a variety of plant tissues, and as an intermediate in the oxidation of methionine to the sulfone. Its absorption spectrum has not been recorded. The sulfoxide chromophore is usually a broad band, located around 2100 A and of about the same intensity as alkyl sulfides (Koch, 1950). An interesting... [Pg.323]


See other pages where Methionine, sulfoxide 2-amino-4- is mentioned: [Pg.852]    [Pg.852]    [Pg.830]    [Pg.167]    [Pg.121]    [Pg.136]    [Pg.22]    [Pg.602]    [Pg.234]    [Pg.831]    [Pg.93]    [Pg.109]    [Pg.113]    [Pg.117]    [Pg.90]    [Pg.94]    [Pg.172]    [Pg.209]    [Pg.223]    [Pg.227]    [Pg.851]    [Pg.293]    [Pg.294]    [Pg.173]    [Pg.692]   


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Methionine sulfoxide

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