The biochemical properties of two species of methionine transfer ribonucleic acid from bakers’ yeast, separated by diethylaminoethyl Sephadex column chromatography, have been studied. Each species of the two methionine tRNAs, designated methionine tRNA I and methionine tRNA II, respectively, has been purified by benzoylated DEAEcellulose column chromatography. Methionine tRNA I can be esterifie...

Hartley (4) has reported the amino acid sequence of a 25-residue peptide from the tryptic digest of X-sulfochymotrypsinogen which contains the “active center” serine as well as both methionine residues of a-chymotrypsin (Fig. 1). By kinetic analysis, Ray et al. (5, 6) deduced that 1 of the 2 methionine residues and 1 of the 2 histidine residues in chymotrypsin are rapidly destroyed on photo-oxi...

A large proportion of human tumor-derived cell lines and primary tumor cells show methionine-dependent growth. This phenomenon refers to the ability of cells to grow in media containing methionine and the inability of cells to grow in media supplemented with methionine's precursor, homocysteine (Hcy). Methionine can be formed by two different pathways, the recycling pathway and the salvage path...

Reactive oxygen intermediates generated by neutrophils kill bacteria and are implicated in inflammatory tissue injury, but precise molecular targets are undefined. We demonstrate that neutrophils use myeloperoxidase (MPO) to convert methionine residues of ingested Escherichia coli to methionine sulfoxide in high yield. Neutrophils deficient in individual components of the MPO system (MPO, H(2)O...

Poultry meat is an important source of zoonotic Salmonella infection. Oral vaccination of chickens with live attenuated Salmonella during grow-out is an attractive approach to control Salmonella colonization in the chicken gastrointestinal tract. In this study, we report the construction of methionine-dependent and growth of Salmonella Typhimurium mutant strains with methionine auxotrophy (Δmet...

The interaction of the effect of dietary methionine on the availability of hepatic glutathione (GSH) and the effect of chronic ethanol (EtOH) consumption on the activity of the hepatic oxidation system was studied in relation to acetaminophen (ACAP) metabolism in mice. Adult male Swiss-Webster mice were pair-fed for 4 wk an EtOH-containing liquid diet that provided 50 or 100% of the methionine ...

1. An automated colorimetric method for determination of methionine using an iodoplatinate reagent is described. Methionine sulphoxide does not react under the chosen conditions. 2. The method may be used to distinguish between unoxidized and total methionine by doing one determination without and one determination with previous reduction of a portion of the sample with titanium trichloride. Me...