Tyrosine aminotransferase: The entrypoint enzyme of the tyrosine-derived pathway in rosmarinic acid biosynthesis

  title={Tyrosine aminotransferase: The entrypoint enzyme of the tyrosine-derived pathway in rosmarinic acid biosynthesis},
  author={Wanchai De-Eknamkul and Brian E. Ellis},

Behavior of Free Aromatic Amino Acid Pools in Rosmarinic Acid-Producing Cell Cultures of Anchusa officinalis L.

It is suggested that there exists a close coupling between the l-tyrosine pool and the rosmarinic acid biosynthetic pathway, which may involve the channelling of intermediates both into and within the pathway.

Rosmarinic acid formation and differential expression of tyrosine aminotransferase isoforms in Anchusa officinalis cell suspension cultures

Both T AT-1 and TAT-4 are closely involved in RA biosynthesis, as well as the substrate specificity of each TAT isoform.

Tyrosine Aminotransferase Contributes to Benzylisoquinoline Alkaloid Biosynthesis in Opium Poppy1[W]

The modest correlation between transcript levels and BIA accumulation in opium poppy supports a role for TyrAT in the generation of alkaloid precursors, but it also suggests the occurrence of other sources for 4-hydroxyphenylacetaldehyde.

Identification and biochemical characterisation of tyrosine aminotransferase from Anthoceros agrestis unveils the conceivable entry point into rosmarinic acid biosynthesis in hornworts

This work presents the first description of a heterologously expressed TAT from a hornwort and describes the possible entry into the biosynthesis of RA and other specialised compounds in a so far neglected representative of terrestrial plants and upcoming new model organism.

Phenylalanine ammonia-lyase (PAL) gene activity in response to proline and tyrosine in rosemary callus culture

Investigation of the PAL gene activity in the callus of rosemary due to exogenous application of L-proline and L-tyrosine found that it was found that RA production increased significantly at low proline application, while tyrosine application at low concentrations had no effect on RA accumulation, while high tyrosin concentration increased RA accumulation.

The biosynthesis of rosmarinic acid in suspension cultures of Coleus blumei

All the enzymes necessary for the formation of rosmarinic acid from the precursors phenylalanine and tyrosine could be isolated from cell cultures of Coleus blumei, and the main characteristics of these enzymes of the proposed biosynthetic pathway of roedic acid will be described.

Biosynthesis and Accumulation of Rosmarinic Acid in Plant Cell Cultures

The regulation of RA biosynthesis and accumulation on the enzyme as well as the gene level is studied in the model system Coleus blumei, which contributes to the pharmacological and food-preserving qualities of these plants.

Molecular Cloning and Characterization of Tyrosine Aminotransferase and Hydroxyphenylpyruvate Reductase, and Rosmarinic Acid Accumulation in Scutellaria baicalensis

The transcript levels of TAT isoforms and HPPR were higher than those in other organs and RA was also highly accumulated in the flowers and with a trace amount in the roots, helping in elucidating the mechanisms of RA biosynthesis in S. baicalensis.



The reaction of amino-oxyacetate with pyridoxal phosphate-dependent enzymes.

The carbonyl reagent amino-oxyacetate is frequently used in metabolic studies to inhibit individual pyridoxal phosphate enzymes and inhibition by dopa (3,4-dihydroxyphenylalanine) decarboxylase was studied to determine the extent to which the inhibition is reversible and the rates at which it takes place.

Tyrosine aminotransferase. Purificaton and characterization.

Tyrosine aminotransferase was highly purified from rat livers in which the enzyme had been induced by a glucocorticoid hormone, and has a bell-shaped pH-activity curve with a maximum near pH 7.5.

l-Ornithine:2-Oxoacid Aminotransferase from Squash (Cucurbita pepo, L.) Cotyledons: Purification and Properties.

2-oxoacid aminotransferase (EC has been purified over 400-fold with a total recovery of 14% from acetone powders of cotyledons of germinating squash (Cucurbita pepo, L.) seedlings with evidence for the unequivocal involvement of pyridoxal phosphate inconclusive.

Amino Acid Metabolism in Plants. III. Purification and Some Properties of a Multispecific Aminotransferase Isolated from Bushbean Seedlings (Phaseolus vulgaris L.)

All three aromatic amino acid – α-ketoglutarate aminotransferase activities were found to have similar patterns of development in comparable organs grown under the two environmental conditions, and the changes in levels of activity appeared unrelated to variations in the endogenous amounts of free aromatic amino acids in the organs of these seedlings.

Culture methods and detection of glucanases in suspension cultures of wheat and barley.

The presence of a laminaranase (endo-β-(1 → 3)-D-glucan glucanohydrolase (EC that did not attack lichenan was established and the culture media of the wheat contained an oligosaccharide which on acid hydrolysis yielded galactose, arabinose, and xylose.