Asparaginase catalyses the hydrolysis of the amino acid asparagine to aspartic acid and ammonia. The asparaginase enzyme preparation described in the Novozymes’ dossier is intended for use during food processing to reduce the level of asparagine and thereby to decrease the risk of acrylamide formation. Acrylamide is formed in food from asparagine and reducing sugars when food products are baked...

Asparagine synthetase (AS) catalyzes the ATP-dependent conversion of aspartate into asparagine using ammonia or glutamine as nitrogen source. There are two distinct types of AS, asparagine synthetase A (AS-A), known as strictly ammonia-dependent, and asparagine synthetase B (AS-B), which can use either ammonia or glutamine. The absence of AS-A in humans, and its presence in trypanosomes, sugges...

Overall autophagy was measured in isolated hepatocytes as the sequestration and lysosomal hydrolysis of electroinjected [14C]lactose, using HPLC to separate the degradation product [14C]glucose from undegraded lactose. In addition, the sequestration step was measured separately as the transfer from cytosol to sedimentable cell structures of electroinjected [3H]raffinose or endogenous lactate de...

We analyzed the effect of asparagine starvation and L-asparaginase on RNA metabolism of mouse leukemia cell lines L5178Y, whose growth is dependent on the presence of asparagine, and L5178Y-R, whose growth is independent of the presence of asparagine. The deprivation of asparagine from the medium inhibited cellular protein synthesis by 30 to 40% of the control value in L5178Y cells, but not in ...

The enzyme asparaginase, which hydrolyses asparagine to aspartic acid, inhibited cell-free protein synthesis by reticulocyte lysates. The inhibition was rapid and complete when sufficient enzyme was added but could be prevented or reversed by the addition of asparagine. The initial effect of asparaginase appears to be a block in polypeptide chain elongation due to asparagine deprivation, but th...

Pyrimethamine analogs were examined as potential agents against vivax malaria using a bacterial surrogate system carrying Plasmodium vivax dihydrofolate reductase-thymidylate synthase (PvDHFR-TS), in which the PvDHFR complemented chemically knocked out host dihydrofolate reductase. The system was initially tested with P. falciparum dihydrofolate reductase-thymidylate synthase and was found to h...

Asparagine synthetase activity in cereals has become an important issue with the discovery that free asparagine concentration determines the potential for formation of acrylamide, a probably carcinogenic processing contaminant, in baked cereal products. Asparagine synthetase catalyses the ATP-dependent transfer of the amino group of glutamine to a molecule of aspartate to generate glutamate and...

background l-tryptophan is an important ingredient in medicines, especially in neuromedicines such as antidepressants. many commercial processes employ various microorganisms with high tryptophan synthase activity to produce l-tryptophan from indole and l-serine, but these processes are very costly due to the costs of precursors, especially l-serine. objectives for this reason, we studied the a...

peppermint has considerable commercial value and widely cultivated for essential oil production, especially menthol. the aim of this study was to determine the quantitative expression of pulegone reductase (pr), menthofuran synthase (mfs) and limonene synthase (ls) genes in menthol biosynthesis pathway in mentha x piperita , using semiquantitative rt-pcr analysis and evaluating menthol producti...