Osmoprotectant beta-alanine betaine synthesis in the Plumbaginaceae: S-adenosyl-L-methionine dependent N-methylation of beta-alanine to its betaine is via N-methyl and N,N-dimethyl beta-alanines.
Mechanism of L-methionine overproduction by Escherichia coli: the replacement of Ser-54 by Asn in the MetJ protein causes the derepression of L-methionine biosynthetic enzymes.
Patterns of protein synthesis and tolerance of anoxia in root tips of maize seedlings acclimated to a low-oxygen environment, and identification of proteins by mass spectrometry.
New routes for lignin biosynthesis defined by biochemical characterization of recombinant ferulate 5-hydroxylase, a multifunctional cytochrome P450-dependent monooxygenase.
Histidine is special in that its biosynthesis is inherently linked to thepathways of nucleotide formation. Histidine residues are often found in enzymeactive sites, where the chemistry of the imidazole ring of histidine makes it anucleophile and a good acid/base catalyzer. We now know that RNA can havecatalytic properties, and there has been speculation that life was originallyRNA-based. Perhaps the transition to protein catalysis from RNA catalysisoccurred at the origin of histidine biosynthesis.
Ergot alkaloid biosynthesis in Aspergillus fumigatus: overproduction and biochemical characterisation of a 4-dimethylallyltryptophan N-methyltransferase.
These compounds include tosylate, disulfate tosylate, disulfate ditosylate, and 1,4-butanedisulfonate and are typically written immediately after the chemical name of SAM-E.
Inhibition of glutathione synthesis with propargylglycine enhances N-acetylmethionine protection and methylation in bromobenzene-treated Syrian hamsters.
Crystal structure of the S-adenosylmethionine synthetase ternary complex: a novel catalytic mechanism of S-adenosylmethionine synthesis from ATP and Met.
Further insight into S-adenosylmethionine-dependent methyltransferases: structural characterization of Hma, an enzyme essential for the biosynthesis of oxygenated mycolic acids in Mycobacterium tuberculosis.
The enzyme is also regulated by covalent modification (adenylylation of a Tyrresidue), which results in an increase sensitivity to the cumulative feedbackinhibition by the above nine effectors. Adenylyltransferase is the enzyme whichcatalyzes both the adenylylation and deadenylylation of E. coli glutaminesynthetase, and this enzyme is complexed with a tetrameric regulatory protein, PII.Regulation of the adenylylation and its reverse occurs at the level of PII,depending upon the uridylylation of another Tyr residue, located on PII.When PII is uridylylated, glutamine synthetase is deadenylylated; thereverse occurs when UMP is covalently attached to the Tyr residue of PII.The level of uridylylation is, in turn, regulated by the activities of the twoenzymes, uridylyltransferase and uridylyl-removing enzyme, both located on thesame protein. Uridylyltransferase is activated by -ketoglutarateand ATP, while it is inhibited by glutamine and Pi.
Citicoline helps energize brain cells while optimizing the neural electrical impulses that power all thought. Citicoline also helps synthesize phosphatidylcholine (PC), the major phospholipid found in brain cell membranes. In combining brain energy + phospholipid synthesis, citicoline may be uniquely qualified for the intensive task of brain cell regeneration and repair. Citicoline also supports neurotransmitters, including acetylcholine, while supplying brain-protective antioxidant activity.
Effects of S-adenosyl-L-methionine disulfate tosylate salt and L-methionine (L-Met) on rat erythrocytes and primary cultured hepatocytes were studied.