The effects of amino acid intake on protein synthesis in the intact rat appear to be mediated almost entirely by a single amino acid: leucine. The effect of leucine on protein synthesis appears to be closely associated with eIF4G phosphorylation and its association with eIF4E, but whether eIF4G phosphorylation actually mediates the effects of leucine or is merely associated with these events ha...

N a previous communication (CALVO, FREUNDLICH and UMBARGER 1969), a I group of Salmonella typhimurium mutants was described as having the following properties. They were resistant to an analog of leucine, 5’,5’,5’-trifluoroDL-leucine (RENNERT and ANKER 1963), excreted leucine, had constitutive and derepressed levels of enzymes involved in leucine biosynthesis, and they had mutant sites linked t...

For the same infusion site of L-[1-14C]leucine, sampling downstream of arterial blood underestimates leucine turnover, whereas sampling of venous blood overestimates turnover. Further, the lungs release a small but consistent amount of leucine into the blood. Unlabelled leucine also is produced by the portal-drained viscera, and some is removed immediately by the liver. These sources of leucine...

BACKGROUND Leucine is a key amino acid involved in the regulation of skeletal muscle protein synthesis. OBJECTIVE We assessed the effect of the supplementation of a lower-protein mixed macronutrient beverage with varying doses of leucine or a mixture of branched chain amino acids (BCAAs) on myofibrillar protein synthesis (MPS) at rest and after exercise. DESIGN In a parallel group design, 4...

This study is aimed at screening non-Saccharomyces for amino acids decarboxylation potentials. The yeasts were isolated from banana fruit and honey purchased markets in Rivers State. isolation molecular identification of yeast isolates according to standard microbiological procedures. A plate assay method acid (biogenic amine production) was used. Wild Non-Saccharomyces (NSY) identified as Cand...

The leucine operon of Salmonella typhimurium is controlled by a transcription attenuation mechanism. Four adjacent leucine codons within a 160-nucleotide leu leader RNA are thought to play a central role in this mechanism. Three of the four codons are CUA, a rarely used leucine codon within enteric bacteria. To determine whether the nature of the leucine codon affects the regulation of the leuc...

The purpose of present review is to describe the effect of leucine supplementation on skeletal muscle proteolysis suppression in both in vivo and in vitro studies. Most studies, using in vitro methodology, incubated skeletal muscles with leucine with different doses and the results suggests that there is a dose-dependent effect. The same responses can be observed in in vivo studies. Importantly...

This study determined the effect of nutritional supplementation throughout endurance exercise on whole-body leucine kinetics (leucine rate of appearance [Ra], oxidation [Ox], and nonoxidative leucine disposal [NOLD]) during recovery. Five trained men underwent a 2-h run at 65% VO(2max), during which a carbohydrate (CHO), mixed protein-carbohydrate (milk), or placebo (PLA) drink was consumed. Le...

Leucyl transfer ribonucleic acid synthetase (EC 6.1.1.4, L-leucine: tRNA ligase (AMP)) has been purified from Escherichia coli and is free of other aminoacyl-tRNA synthetases, tRNA-methylating enzymes, and CpCpA-adding enzymes. Several criteria suggest that there is one synthetase with specikity for two forms of leucine-specik tRNA which can be separated by countercurrent distribution: purifica...