Methionine limitation during growth and sporulation of a methionine-requiring diploid of Saccharomyces cerevisiae causes two significant changes in the normal synthesis of ribonucleic acid (RNA). First, whereas 18S ribosomal RNA is produced, there is no significant accumulation of either 26S ribosomal RNA or 5.8S RNA. The effect of methionine on the accumulation of these RNA species occurs afte...

It is well known that caloric restriction leads to an increased longevity by forestalling age-related diseases. Dietary restriction of methionine also renders similar benefits. In this review, we report studies on the effect of methionine restriction on epithelial barrier function in a renal epithelial LLC-PK1 cell, a rodent gastrointestinal model and a clinical trial using Crohn’s patients. In...

Pigs (n 100) between 28 and 56 d of age were given diets containing one of five protein concentrates ad lib. The utilization of methionine from the protein concentrates was compared with synthetic methionine. Increasing the methionine content of the diets from 1.5 to 2.2 g/kg diet increased the weight gains of the pigs from 61 g/d to 198-292 g/d. The feed conversion efficiencies decreased from ...

Evidence is presented that Lemna converts 5'-methylthioadenosine (MTA) to methionine. The methylthio moiety and four of the ribose carbons of the nucleoside contribute the methylthio and the four-carbon moieties of methionine. Plants grown in the presence of inhibitors which block methionine biosynthesis convert MTA to methionine at a rate sufficient to sustain normal growth (at least 4.4 nanom...

It has been shown previously (1,2) that the synthesis of CO-NH linkages by papain as well as by other proteinases is characterized by extreme stereochemical specificity. Thus, upon the addition of cysteine-activated papain to a mixture of carbobenzoxy-nn-glutamic acid and aniline, there is formed carbobenzoxy-L-glutamic acid anilide, which separates in crystalline form. The carbobenzoxy-n-gluta...

Perfused rat hindquarter preparations were shown to incorporate radioactivity from [U-14C]methionine into citrate-cycle intermediates, lactate, alanine, glutamate, glutamine and CO2. During perfusion, large amounts of methionine were also oxidized to methionine sulphoxide. The capacity for transamination of methionine or its oxo analogue, 4-methylthio-2-oxobutyrate, by muscle extracts was demon...

Tessari, Paolo, Edward Kiwanuka, Anna Coracina, Michela Zaramella, Monica Vettore, Anna Valerio, and Giacomo Garibotto. Insulin in methionine and homocysteine kinetics in healthy humans: plasma vs. intracellular models. Am J Physiol Endocrinol Metab 288: E1270–E1276, 2005. First published January 11, 2005; doi:10.1152/ajpendo.00383.2004.—Methionine is a sulfur-containing amino acid that is reve...

A simple assay for the detection of 35S-labeled methionine sulfoxide residues in proteins is described. The assay, which is based on the ability of CNBr to react with methionine but not with methionine sulfoxide, requires the prelabeling of cellular proteins with [35S]methionine. The assay was used to study the extent of methionine oxidation in newly synthesized proteins of both activated and q...

Ruminants have high concentrations of peptide-bound amino acids in the circulation. Earlier studies in our laboratory showed that a myogenic cell line (C2C12) developed from mouse skeletal muscle and a mammary epithelial cell line (MAC-T) developed from bovine mammary epithelial tissues are able to utilize peptides as amino acid sources. In this study, primary cultures of ovine myogenic satelli...

This study aimed to evaluate liver and breast muscle insulin-like growth factor I (IGF-I) and growth hormone receptor (GHR) gene expression between broilers fed different methionine levels and sources. Broiler chicks were 22 to 42 days old, distributed in 5 treatments (control diet, DL1 - 0.08% DL-methionine, DL2 - 0.24% DL-methionine, MHA-FA1 - 0.11% methionine hydroxy analogue-free acid, and ...