this study was conducted to compare the bio-efficacy of herbal methionine (h-met) relative to dl-methionine (dl-met) on 160 “ross 308” broiler chickens. dl-met and h-met were added to the basal diet in eight experimental treatments with three and four concentrations respectively in starter, grower and finisher period. blood parameters which were measured at 24 and 42 days of age consisted of: s...

wide range of products is available; from inorganic, sodium selenite or selenate coated or not, even nanoparticles to organic forms such as selenized yeasts, chelates of selenium methionine (SeMet), pure forms of SeMet or hydroxy-selenomethionine, and some complexes sources of Se based on mixing mineral Se with glycinates, proteinates, etc. It has been confirmed that, comparing with mineral sel...

Besides being building blocks for protein synthesis, amino acids serve a wide variety of cellular functions, including acting as metabolic intermediates for ATP generation and for redox homeostasis. Upon amino acid deprivation, free uncharged tRNAs trigger GCN2-ATF4 to mediate the well-characterized transcriptional amino acid response (AAR). However, it is not clear whether the deprivation of d...

background : increased level of serum homocysteine is one of the risk factor of atherosclerosis. its production related in some sulfur amino acids such as methionine. some important cofactors that are involved in metabolic pathways of this amino acid are folate and vitamin b12. we have assessed the status of methionine, folic acid, and vitamin b12 in some coronary atherosclerotic male patients....

Impaired transfer of methyl groups via the methionine cycle leads to plasma hyperhomocysteinemia. The tissue sources of plasma homocysteine in vivo have not been quantified nor whether hyperhomocysteinemia is due to increased entry or decreased removal. These issues were addressed in female rats offered diets with either adequate or excess methionine (additional methyl groups) with or without f...

Amino acid dehydrogenases (L-amino acid: oxidoreductase deaminating EC 1.4.1.X) are members of the wider superfamily of oxidoreductases that catalyze the reversible oxidative deamination of an amino acid to its keto acid and ammonia with the concomitant reduction of either NAD+, NADP+ or FAD. These enzymes have been received much attention as biocatalysts for use in biosensors or diagnostic kit...

As part of a survey to determine the suitability of microorganisms as sources of protein and amino acids, the lysine, methionine, and tryptophan in the cells of 271 strains of yeasts were determined. Yeast cells are an established source of proteins and vitamins in feeds. As a group, yeast possess certain advantages for large-scale propagation of cells. They can be grown easily on a variety of ...

The sources and mechanisms of gas production by irradiation were determined using model systems prepared with fatty acid, phospholipids, oil, sugars, glycolysis and TCA cycle intermediates, nucleic acids, amino acid monomers and homopolymers, and proteins. The model systems were irradiated at 0, 2.5, 5, or 10 kGy using a linear accelerator and the amounts of CO, CO 2, and CH4 produced were dete...

In this paper, we present a novel, "single experiment" methodology based on genetic engineering of metabolic pathways for direct intracellular production of non-canonical amino acids from simple precursors, coupled with expanded genetic code. In particular, we engineered the intracellular biosynthesis of L-azidohomoalanine from O-acetyl-L-homoserine and NaN3, and achieved its direct incorporati...

The steady-state kinetic parameters of pyridoxal 5'-phosphate-dependent recombinant methionine γ -lyase from three pathogenic bacteria, Clostridium tetani, Clostridium sporogenes, and Porphyromonas gingivalis, were determined in β- and γ-elimination reactions. The enzyme from C. sporogenes is characterized by the highest catalytic efficiency in the γ-elimination reaction of L-methionine. It was...