The previously reported inability of methionine to stimulate cephalosporin C production in a cysteine auxotroph is due to cysteine interference with methionine uptake. In such a cse, "illicit transport" of alanylmethionine can be used to demonstrate the efficacy of methionine in such mutants blocked in the path from methionine to cysteine. This result supports the hypothesis that the stimulator...

a total of 160 day-old male broiler chickens (ross 308) were divided in a completely randomized design experiment, and assigned to 8 treatments and 4 replicates in their experimental units (cages). treatments included: t1: basal diet with no additional methionine, t2: basal diet plus 0.06, t3: basal diet plus 0.11, t4: basal diet plus 0.17 % of dl-methionine, t5: basal diet plus 0.06, t6: basal...

this experiment was conducted in international researchery institute of sturgeon fishes shahid  dadman. the basal diet contained fish meal as protein source (cp=40%). five diets were supplemented with 5 graded levels of methionine, (0, 0.5,1 ,1.5, 2% met per kg diet) . each diet was randomly assigned to triplicate groups of 195 juvenile huso huso (initial weight 31.9± 2.8) in fiftin 500-l circu...

In immature rib segments prepared from morning-glory (Ipomoea tricolor) flower buds, the major soluble metabolite formed from tracer amounts of l-methionine-U-(14)C was S-methylmethionine (SMM). In segments of senescing ribs, (14)C was progressively lost from SMM and appeared in free methionine. Immature segments contained about 4 nmoles of free methionine and about 16 nmoles of SMM per 30 segm...

Extensive research on the formation of methionine has implicated vitamin B12 as a cofactor in the final reaction of the biosynthetic sequence. Since plants and fungi do not produce or require B12, an alternate reaction must also exist. It is thus not surprising that Escherichia coli has been found to possess two mechanisms for the methylation of homocysteine to methionine (9). These reactions a...

Corynebacterium glutamicum is known for its effective excretion of amino acids under particular metabolic conditions. Concomitant activities of uptake and excretion systems would create an energy-wasting futile cycle; amino acid export systems are therefore tightly regulated. We have used a DNA microarray approach to identify genes for membrane proteins which are overexpressed under conditions ...

A methionine-restricted diet robustly improves healthspan in key model organisms. For example, methionine restriction reduces age-related pathologies and extends lifespan up to 45% in rodents. However, the mechanisms underlying these benefits remain largely unknown. We tested whether the yeast chronological aging assay could model the benefits of methionine restriction, and found that this inte...